On a recent Sunday morning in Los Angeles, Mark Ruffalo woke up to a ringing phone. His friend was on the line, talking the actor out of his pajamas and over to his Malibu house, where folks were gathering for a barbecue. So along with his wife, Sunrise, a French-born boutique owner, and their 3-year-old son, Keen, Ruffalo spent the day in the pool, laughing children hanging from his every limb. ''I guarantee you that if you want to find Mark at a party,'' says ''We Don't Live Here Anymore'' director John Curran, ''he'll be with the kids running down the beach. They gravitate toward him like a magnet. I think he gets bored with adult talk.''
Ruffalo enjoyed himself so much that he ended up missing our interview, previously arranged for 6 o'clock at a Hollywood deli. Three hours, 15 frantic messages from his publicist and manager on his cell phone later, he's downstairs at my hotel, in a long-sleeved T-shirt and cargo pants, hair thick and curly from chlorine, grinning sheepishly. ''Oh. My. God. I'm so, so sorry. I completely forgot and I was having the best day and I'm such a schmuck.''
With two movies coming out this month -- ''We Don't Live Here Anymore,'' an intense study of two marriages in crisis, and Michael Mann's chest-thumper ''Collateral'' -- he's running ragged. So however sad it was being stood up, the waiters clucking in sympathy as they cleared the second table setting, it's hard to begrudge this man -- so suddenly in demand and so deeply conflicted about the pull of fame -- an afternoon off.
When Ruffalo first moved to California after high school, the Wisconsin native spent half a year surfing before he committed to acting. He's still got something of a stoner's drawl, a marble-mouthed delivery that's slow and relaxed. ''I'm juicing it, man,'' he tells the hotel bar's moony-eyed waitress, who lingers after his cranberry-orange request, soaking up the actor's smiling face and his dagger of an Adam's apple.
It wasn't long ago that Ruffalo, 36, was on her side of the drink order. In leaner times, he supported his independent theater work and training at the prestigious Stella Adler academy with 10-hour bartending shifts at L.A. hot spots like Small's and the Chateau Marmont. ''People doing blow off some stripper's chest,'' he says, grimacing at the memory, ''all of them in the business, all of them who are supposed to be at work at 7 o'clock in the morning, shooting their next picture.'' His old roommate Christopher Thornton remembers Ruffalo coming home hopeless: ''He'd say, 'Not only do I not know if this is ever going to happen for me, but even if it does, is this what I'm looking at? Am I going to be one of these four-martini a -- holes?'''
In 1996, Ruffalo left Hollywood for New York, where he finally earned attention with his startlingly fine stage performance as a 19-year-old burn-out in Kenneth Lonergan's hit Off Broadway play ''This Is Our Youth.'' ''I was terrified of going to New York and doing the play,'' he says. ''But that place is the very seat of whatever success I've had. If you're an artist, you go to New York. That's it.'' Lonergan would then tap Ruffalo for the breakthrough role of Terry, an orphaned drifter who goes home to visit his sister (Laura Linney), in ''You Can Count on Me.'' (And if you haven't yet seen that quiet marvel of a movie, which earned Lonergan a best-screenplay Oscar nod, put down this magazine immediately and rush to the closest video store.)