Robert Downey Jr. doesn't work out like us regular folks. Adulation bathes him from the moment he arrives at his Los Angeles martial arts studio. He opens the front door and is greeted by a framed photo of himself with his trainer and his 16-year-old son, Indio. The inscription reads: SIFU, INDIO AND I ARE AVAILABLE FOR PERSONAL PROTECTION. He takes another step. Before you can hum the opening bars to "Cult of Personality," there's an even larger blowup of a 'Los Angeles Times' story, about some dude named Robert Downey Jr. slaying all the bad guys in his mind. Six-pack abs would be so much easier if this kind of positive reinforcement were available at the Y.

Downey is carrying a small black box. The box's contents are not readily apparent. He puts the box down gently and pulls on a prison-orange hoodie. The effect enlarges his brown puppy-dog eyes to Japanese anime proportions. He bows to Eric Oram, the owner of the studio.

"Good morning, sifu."

Sifu is what instructors are called in Wing Chun, a martial arts discipline that has been Downey's religion since 2003. That's around the time he dropped the drugs that molted him from Oscar nominee to celebrity death pool nominee. Wing Chun is considered the sensitive artist's kung fu – Bruce Lee was its first celebrity spokesman – because it's all about balance, peace, and, if all else fails, ass-whipping. These skills are particularly important in Hollywood.

We step onto the mat. While Downey has been practicing Wing Chun for almost seven years, I have been practicing Wing Chun for almost seven minutes. "Seriously, don't worry about looking like an idiot," he tells me. "It's like life: The less self-conscious you are, the better it works. And remember, lots of ice and Advil afterward. Trust me on that one."

We do breathing exercises, stretch a while, and then toss a small ball around, working on reaction time. Downey muffs one. He shoots Oram a busted schoolboy look. Oram flashes a sadistic smile.

"That's 10," he barks at Downey.

Downey drops and gives him 10 push-ups. Many former addicts talk of trading the addiction of drugs for the addiction of exercise. Downey's one of them. The more he sweats, the more he enters an opiate-free nirvana. "I love this," he whispers. "Isn't it awesome?"

I'm just trying not to hurl. We move to a hand-to-hand fighting exercise. "You don't want to fight the truck," says Oram, a bald man with intense eyes and even more intense eyebrows. "You want to step out of the way of the truck. Once you step out of the way, you can start throwing rocks at the truck." Downey nods and tugs at his hoodie.

"This is all about focus," Downey tells me between reps. "Wing Chun teaches you what to concentrate on, whether you're here or out in the world dealing with problems. It's second nature for me now. I don't even get to the point where there's a problem."

Oram raises his hand to punch, and Downey slaps away his elbow and then counters to Oram's neck. The two do an elaborate, fistic dance for five minutes. There's just one hitch in Downey's giddyap. He repeatedly raises his right hand to block a phantom ear punch Oram never throws, perhaps a leftover ghost from having to protect himself in the jails he frequented in the late '90s. No amount of Wing Chun can make that go away.

After an hour, we're done. Well, I'm done. Downey keeps working. He pounds on a wooden dummy blocking with one hand and then delivering a combination to a padded face. He lets out a series of grunts and grimaces. A grin slips across his face.

"The word to describe Robert is hard," says Guy Ritchie, Downey's director on Sherlock Holmes. "I know that's fucking ridiculous in describing an actor, but he can really scrap. He's done time in jail, which didn't exactly soften him up. He has a real physicality that is pretty fucking amazing."

In the Arthur Conan Doyle books, Holmes dabbles in martial arts, so Ritchie, Downey, and Oram took some liberties and collaborated to make Sherlock a buff badass. During a key fight scene, Holmes boxes with a behemoth, and Downey was reluctant to punch the British stuntman full in the mouth at first.

"I was like, 'I can't or he's not going to be able to play with his kids this weekend,' " recalls Downey. "And Guy was basically saying, 'He doesn't have any kids.' "

Downey complied. By the end of the day, the stuntman's face was red and swollen.

No one gets beaten up that bad at the martial arts center today, but Oram finally has to tell Downey that's enough.

"Sifu, I'm worried about my exam," says Downey, after a shower. He hopes to move up the Wing Chun achievement ladder from green to brown belt – one level away from black belt.

"You will do fine," says Oram solemnly. "Or you won't."

Oram and Downey have a classic codependent relationship that goes something like this: Oram teaches Downey three to five days a week, Downey stays clean and sane, and Oram comes to his movie sets, where he serves as confessor, guru, and fight consultant. He then gets to plaster Downey's name and picture all over his gym and literature.

"When he first came to me, insurance companies wouldn't bond him for movies; he couldn't get roles," Oram says. "I told him if he didn't show up to a lesson, I was going to chop off his toes and feed them back to him. One day he didn't turn up, and I told him goodbye. Then he had a couple of producers call me and vouch for him, saying, 'He was with us in a meeting; he didn't have a phone. It's our fault. Don't cut his head off.' He has committed himself to it ever since and turned his life around."

"Wing Chun is all about guarding your center line," Downey tells me, talking about the place where touchy-ouchy martial art meets philosophy of life. "Don't fight force with force; use two hands at the same time; concentrate on your own thing; and after you have that dialed in, effect the balance, look for openings, look for arms to be crossed."

So that's the secret to his newfound prosperity?

"Oh, yeah, dude," says Downey.I'd met Downey once before under less serene circumstances. It was in 1992 at the Republican National Convention in Houston. The heat was nearly as oppressive as Pat Buchanan. Downey was filming a gonzo political documentary, and I was self-medicating with a friend who was working for the Bush-Quayle campaign. Downey and I had a happily incoherent conversation that ended with one of us excusing ourselves, possibly to vomit.

The trip for me was a boys' weekend gone horribly wrong. It was Downey's daily life for more than a decade. After a brilliantly diffuse early career – there were starmaking turns in 'Chaplin' and, uh, 'Weird Science' – he seemed hell-bent on reenacting all the drug scenes from his early classic 'Less Than Zero'. It's hard to remember if the most depressing part of Downey's downward spiral was his going to prison for heroin possession and a gun charge; passing out in his neighbor's bed, thinking it was his own; or getting hired and fired from Ally McBeal.

By 2006 Downey was longtime clean, but he was still playing the sixth lead in a remake of 'The Shaggy Dog', the thespian equivalent of opening for a puppet show. But then came 'Iron Man,' 'Tropic Thunder,' and 'Sherlock Holmes.' The three films together grossed $1.25 billion – more than the 50-plus Downey films that preceded them.

Now, at 45, everyone wants a piece of him, including sifu's earlier client, a director who would just love to meet Robert. "He's done commercials," says Oram, without pushing too hard. Downey remains serene, nods affirmatively, and speaks few words – a rarity for him.

This meeting is never going to happen.

Downey, of course, is grateful he has moved from Tom Sizemore problems to Tom Cruise problems. Still, there's a paradox: The success of 'Iron Man' has opened the world to Robert Downey Jr., but making too many soulless popcorn flicks may be replacing his former 'Sunset Boulevard' buddies as the biggest threat to his sanity. Even before 'Iron Man 2' hits, 'Iron Man 3' is already in the works, and a 'Sherlock' sequel is in development. All the filming and promoting has left Downey exhausted. I ask if he is worried about burnout.

"You don't worry about something that has already happened," he says with resignation. "You don't need to worry about your car breaking down when you're already on the side of the street with the hood up. Worrying is done. The hubcaps have already come off going around the corners."Downey bows a goodbye to Oram. The actor is hungry, so his driver/babysitter, Jimmy, drives us over to a chic Italian place in Brentwood. Jimmy's been with Downey for years. They have an endearing Bertie and Jeeves relationship, if Bertie were an ex-con movie star and Jeeves were the size of Steelers linebacker Jack Lambert, who is actually Jimmy's cousin.

Downey sprawls in the backseat, still clutching the little black box. We make small talk for a bit, or, more precisely, I make small talk and Downey answers with big talk. A conversation about fatherhood swoops and rises ("You realize you've got this amazing kid, and all of a sudden you don't want to have more days behind you than in front of you") until he tells me of a recent visit he made to the Rubin Museum of Art in New York for an exhibit on Himalayan art and mortality. "You keep going up these stairs, and it's all about death, and by the time you get to the top, I was like, 'Wow, my life is so minuscule and pointless.'"

The car goes quiet. Jimmy turns up Howard Stern on satellite radio to fill the void. Downey does a bit of a spit take and slaps me on the shoulder. "Dude, no, minuscule is good! Trust me, it's much better than thinking everything you do is important and meaningful. That is not good."

When we get to the Italian place, where Downey is a regular, we settle into a window table. Downey orders a cranberry juice with a lemon. The waiter brings him a cranberry juice. He also brings a bowl of approximately 20 lemon wedges. Every five minutes, Downey adds another lemon to his glass. Within an hour, the glass is a lemon compost pile. He then places the black box on his lap and pops it open. Inside, there's everything but a bunny rabbit: half a dozen containers of vitamins, multiple pieces of Nicorette gum, a nice pen, and a wrapped cigar.

"It's just stuff to keep me healthy," says Downey. His brain is just as happily cluttered. At one point, he makes it clear that despite his recent success, he has not forgotten how low he can go. But he doesn't say it that simply. He speaks in double helixes of metaphors and allusions, taking a straightforward question about how he's doing and answering with a Grateful Dead space-jam drum solo. Some of it sounds beautiful, some of it sounds like the surreal small print of a rental car agreement, which is why I'm shrinking the type size:

"I've seen the folks who the second they hit their critical mass, they essentially shut the door on the story of their past, who they really are, and they become this narcissistic personality disorder version of what they thought they would want to get away from, whatever injury got them to having half of their drive being to get somewhere, because then they could no longer be seen as they see themselves. It's really tricky to see it happen. It's another thing to be put in check by people that I'm close to that sometimes are an accessory in a creative burst. I still have little pilot fish that want to overstate that or centralize that or make it about me. I've noticed more and more lately that, say, we're in a writing session, and Act Three is in desperate need of a breakthrough, and I come up with the idea. I want to, occasionally, parade around and do my 'Where the Wild Things Are' paw-print stomp, and I'd say, 'First of all, it's nice to celebrate, it's nice to be excited, it's another thing to sully that with your own character defects.' Worse still, it's a shame to not see that it's not true, because without the context – and that's why I love partnerships – without the context of somebody who's actually holding the entirety of what we're looking at and what we're doing and what we have to accomplish, rather someone who knows all the challenges inherent in Acts One and Two, and believes, even though we're using a bookmark where the movie ends, where the final image is, that just because it works for now, it works for now because it's comforting, because you believe you have an end. I've been noticing more and more lately how partnerships and small groups of well-matched people are all equally responsible, whether you're the front man in the band or whether you're just mixing behind the scenes. It's awesome."

I know what you're thinking: pilot fish, narcissistic personality disorder, and 'Where the Wild Things Are' all in one thought burst. Downey has fallen off and is now being dragged behind the wagon, right? Not true. It's just Downeyspeak. I mention Downey's tendency to verbally meander to his 'Iron Man 2' co-star Don Cheadle, and he can't stop laughing. "Yeah, I don't know how you're going to pull that off. You're going to need a pictograph, or change the color of the text so people know where he's going. Or just start talking about his socks." Ritchie sums up the Robert Downey Experience succinctly: "Do I have any idea what the fuck he is talking about most of the time? No fucking way. He fucking rants, sounds very clever, and then I have to tell him: 'Repeat that, but this time fucking speak English.' "Downey's brain was molded in a childhood that could be described as bohemian or, less charitably, profoundly fucked up. His father is the indie filmmaker Robert Downey Sr., and in 1970, Dad cast his five-year-old son in the black comedy 'Pound'. Junior's first cinematic line is addressed to a freaked-out bald man: "Have any hair on your balls?" Not exactly the pinewood derby. The storied legend is that Downey Sr. gave Bobby Jr. his first hit of pot when he was eight. Downey's parents split up when he was 12, and he spent a peripatetic childhood shuttling among New York, England, and, finally, Los Angeles, where Downey dropped out of high school just as his father's career began to dry up.

Downey's own son had to endure his addled father being carted off to jail and rehab multiple times. Still, Downey is reluctant to give Indio the "Do as I say, not as I do" speech as he raises his kid on L.A.'s posh west side, not far from many of the places where he first lost his mind to drugs.

"I go through periods of wanting to join hands and sing 'Kumbaya' with everyone, and sometimes I want to fire-bomb the entire area," he says. "All I want, and I think all any parent with a semblance of a moral psychology wants, is for my kid to have his own experience, uninhibited. You want to feed the good dog, because the shadow side of any of us is going to pop up at some point."

Downey doesn't blame his hard times on Pop never scaring him straight. "I grew up with a lot of people whose whole prime mover was dad rage. I never really had it – it always seemed so empty. It always seemed to be masking something else, which was really their own lack of initiative."

He clearly has great respect for his father's left-of-center work – Senior is best known for 1969's 'Putney Swope,' a satire of a black man working in an all-white advertising firm – and cringes at memories of his dad banging his head against Hollywood's studio system. But to say he's worked out his relationship with his 73-year-old father, who now lives in New York, is way too simplistic for a man as smart as Downey. When we talk about 'Iron Man 2', he largely parries questions – until the subject turns to his character Tony Stark's relationship with his dead father.

"We're having Tony go back and really deal with the ramifications of his lack of connection to his dad, his almost professional-stock, prop-smile answers, and how he'd been using Dad's memory as a weapon against others," Downey says. "He's really feeling hugely conflicted by assumptions about his dad's feelings about him and whether or not there's any real connection between them at the most basic level, which is: You're not here anymore for this. Is there something you have for me, is there something you left for me, is there some sort of bread-crumb trail I can find that will help fill me at this point in my life?"

I ask the logical follow-up: Is your relationship with your own dad good? He gives me the only brief answer in the day we spend together.

"Yeah."

Then he squeezes more lemons.When Jon Favreau first raised the idea of casting Downey as Tony Stark, Marvel Studios was so against it that the 'Iron Man' director had to campaign just so that Downey could audition for the part – something he hadn't done since 'Chaplin,' the 1992 film that earned him his first Oscar nomination. Downey said no problem. "You say no if you don't want to do the job," says Downey. "If you want the job, you do whatever's required to meet the specs to have the job."

He started prepping. "I wanted to be perceived as just a little bit more handsome, just a little bit taller. It's all about colors. Sometimes if you're wanting to look just a little bit taller, then you want to dress with just more of a thin cut. Most of all it was to leave them with no option other than to hire me." Downey wore a tailored English suit and slipped on Hogan dress boots to add another inch. But that was all just frosting on the Pop Tart. He already owned the Stark character, a hard-drinking, out-of-control outsider whose swagger camouflages a lifetime of regret and superficial living. In short, the role was not a stretch.

The box office and critical buzz led to Downey being cast as Sherlock Holmes in the Ritchie remake, with Jude Law playing second-banana Watson – a billing hierarchy that would have seemed unthinkable just two years ago. In between those films, Downey scored his second Oscar nomination with 'Tropic Thunder,' playing the dude playing the dude disguised as another dude. According to Downey, the role was the "cathartic experience of my creative life," but in the wrong hands could have won a Razzie, not to mention a censure from the NAACP.

The question now is not whether Downey has the chops to continue as a major movie star, but whether he has the capacity to deal with the bullshit part of the job. It's one thing to always be the dissolute man of great promise; it's another thing to simply be the man.

He rhapsodizes about his experience playing a pompous architect trying to get home for the birth of his child in the recently wrapped 'Due Date,' with 'The Hangover' team of co-star Zach Galifianakis and director Todd Phillips. "My inner asshole was required, and all that stuff that sometimes falls out I was able to use constructively," says Downey. "Working with those guys was probably one of the great experiences of my life."

So far, so good. But then, unprompted, he starts talking about another film that did not take him to his happy place. "There are times when you know you're pushing it and you don't have a great vibe about where things are going creatively. You have to be collarbone-deep in molasses for four months and just go, 'I have no solace in my work whatsoever, and it's 12 hours a day of cosmic punishment.' " He stirs the contents of the black box looking like he might cry. "All I have is what I'm doing when I'm not working, and hopefully that has something to do with taking care of myself."

I ask him which film.

"I will not say its name."

Was it recent?

"Absolutely."

We talk about other things for a while, and I start eliminating movies. I've got it down to two.

Surely, it was The Shaggy Dog, right?

He leans forward and stares hard at me. He gulps down a triple espresso. "'Shaggy Dog' was a very, very important movie for me. It was a very enjoyable experience." He sounds sincere.

Jimmy walks in and reminds Downey of a pending meeting with Ritchie to discuss 'Sherlock Holmes 2' script revisions. We start to wrap things up, and I tell him through my powers of deductive reasoning that his cosmic punishment film must be 'Iron Man 2.' Downey flinches a little, like at the gym trying to ward off the imaginary ear punch.

"This is still art for commerce, at best," says Downey about his chosen profession. "I consider myself to be a pain-in-the-ass artist who's self-aware enough to still be tolerable. While I have a little bit of juice, I try not to rub it in anyone's face, because it's just disgusting. And I use the term 'artist' loosely."Downey takes a couple more vitamins, rummages around the debris in the little black box, closes it, gives a yank at his heart-covered socks, and heads for the door. Jimmy awaits, and we head toward Santa Monica Boulevard and his conference with Ritchie.

"Meetings. I never thought I'd be in so many meetings," says Downey. He's soon off on another tangent, speed-talking about being at a dinner party at producer Joel Silver's house and talking to his Venetian chef and deciding to take his son, Indio, on a cultural vision quest to Italy, staying in three-star-or-less hotels. "Just take a week, just him and me. He's into it; maybe in a year he won't be." Downey, stretching out in the backseat, has put on a long, grandmotherly black sweater. "This is going to happen soon," he insists.

I get the sense that between the production meetings, media junkets, and the next 'Sherlock' flick, the trip probably won't happen. Somehow, Downey has lived long enough to have a "Cat's in the Cradle" moment. But like with most busy, middle-aged fathers, his heart is in the right place. The charismatic, sad, naughty, self-destructive man-child I met in 1992 is long gone, replaced by a sometimes self-rationalizing, sometimes solipsistic grown-up who now knows how to get out of the way of the truck. Something has been lost, and something has been gained.

They drop me off at my car a few minutes later. Downey shakes my hand and slides into the front seat. He gives a wave and, with a little actorly flair, puts on his seat belt. For the first time, I can imagine Robert Downey Jr. living to be a nice old man. The car drives away slowly, never crossing the center line.