The unlikely trigger for all of this was starting a family. He and his longtime girlfriend, the Brazilian model Camila Alves McConaughey, wed last year. They had their first son in 2008—McConaughey boasted at the time of playing Brazilian music for 14 hours straight during labor. A daughter followed two years later, and the couple just had another boy. "He's 34 days old," McConaughey says, sounding tired at the thought.

The whole gang is staying in a rented house in New Orleans, and his wife has laid down the law: Wherever he goes, they go too.

"Papa goes to work, the circus goes with him," he says, pleased.

"I've got a wife who challenges me. There were two movies I wanted to do last year, but they were back-to-back with no separation. She was like, 'You want to do it—buck up, grab your nuts, and make it happen. We'll be there with you.'"

One of the movies he shot in New Orleans is Dallas Buyers Club. McConaughey plays Ron Woodroof in this real-life story of a homophobic Texan who contracts AIDS in the early days of the epidemic and goes to war with the drug companies to try to save his life. To play the emaciated Woodroof, McConaughey aggressively starved himself, dropping 50 pounds in the process.

Jean-Marc Vallée, the French-Canadian director of Dallas Buyers Club, confesses that when his production team first suggested McConaughey for the role, he thought they were crazy.

"I said, 'Really? Matthew for this?'" recalls Vallée. "'Beautiful, muscled Matthew for this?' But I've got to tell you I've been witnessing the most spectacular, amazing, touching acting performance of my humble career so far. He had to create a new way of walking and being and not having this confidence of being handsome and seductive. I think people will see something different here, really a new Matthew McConaughey. I think he wanted something new in his life, and you can see that in the choices he's made in the last two or three years."

"He is who he is, no matter what the project—friendly, funny, and focused," says Jennifer Garner, who's had a chance to observe him on two very different projects, 2009's Ghosts of Girlfriends Past and now in Dallas Buyers Club. "But he was on another plane altogether making this film. I'm not sure if Matthew has changed from fatherhood, marriage, or just regular growing up—but he was more vulnerable and also more scary this time around."

Mud's director, Jeff Nichols, had McConaughey in mind for the title role when he started writing the story in college a decade ago. But he'd never met the actor and wasn't sure what to expect. "This was my first time working with a bona fide movie star," Nichols says. "He'd come straight from Magic Mike, where he was putting Crisco on his body. When he first showed up, he asked for a tent and a sleeping bag. He spent the night alone on this island in the Mississippi where some of the story takes place, just sitting under the tree rereading the script and thinking about this character. That's the kind of thing that, as a director, just makes you feel like you have nothing to worry about."

• • •

"I'm not asking for permission to come in anymore," Matthew McConaughey says. "How do I say that the right way? 'Cause you could take this and make me look like a real asshole."

He refills our glasses, taking a moment to weigh his words carefully.

We're talking about what's changed for him now compared with five years ago. What's different, he says, is he's no longer saying yes to roles simply because he feels lucky.

"I'm just as thankful now as I ever was," McConaughey says. "But I'm choosing to be more selfish. I remember feeling not sure about what I wanted to do and feeling—I'm not sure despondent is the right word, but a feeling like things are plateauing. I wanted more evolution. I want to feel ascension in the grade. Because I was feeling a lot of ascension in my personal life, qualitative evolution. I wanted to close the gap between who I am and the life I'm living and my work life. So I think I got really selfish. You start a family and you get selfish."

By this, he doesn't mean being self-centered. Talk to anyone who's worked with him: The guy's not an asshole. Richard Linklater says, "He's the same now as the guy I was hanging out and eating lunch with during Dazed and Confused. He's a slightly nonlinear deep thinker."