Okay, Smart Guy

He also tells a dark story about a big mistake in his adolescence -- the time when he landed in jail and learned the difference between pulling a prank and being just plain stupid.

And that doesn't even touch on Dolce, the successful Hollywood restaurant hot spot he invested in; or the deal he just signed with MTV to produce a reality series following Oscar-winning rappers Three 6 Mafia.

Leading Man?

"When you invent a character, then you have to struggle to change people's perceptions of you, because it comes with a preconceived notion," Kutcher says. "But I think Olivier said that a wealthy man can always play a beggar, but a beggar can never play a wealthy man. . . . I think you're kind of always trying to move on. You try to push it and you wait for people to sort of catch up to you."

Touchstone Films is gambling that audiences will catch up to the idea of Ashton Kutcher as leading man in a drama (his only previous dramatic performance, in "The Butterfly Effect," was No. 1 its opening weekend at the box office but was critically panned). Not only leading man, but action hero. In "The Guardian," Kutcher plays Jake Fischer, the top trainee at the Coast Guard's elite "A-School" for rescue swimmers; Kevin Costner co-stars as an instructor.

Kutcher wanted in on this movie for 3 1/2 years, but it wasn't until director Andrew Davis ("The Fugitive," "Collateral Damage") and Costner signed on that the project got the green light. And even then, he had to talk his way into the part. So he went to breakfast with Davis, who wanted to figure out why the studio seemed hesitant to sign this particular guy. Davis says he was immediately wowed.

"First of all, he's a great-looking kid," Davis says. "But he was very committed to doing it right and making it real. And he's very smart. He's going to be hugely in demand. He's going to have a huge career, this kid."

The next hurdle, Davis says, was convincing Costner the relationship would work, because "I think all Kevin knew about the guy was the 'That '70s Show' character and the fact that he was married to a big movie star."

Costner confirms all this. His wife, who loves the celebrity magazines, had filled him in on Kutcher's very public personal life, and he'd caught several episodes of the sitcom. And what he saw, he says, was an actor playing a very difficult part very well.

"It's not easy to do comedy and it's not easy to do the good-looking buffoon, because we've seen people try to do that all the time and fail," Costner says, pointing to John Travolta as Vinnie Barbarino on "Welcome Back, Kotter" as an example of someone who did it brilliantly. "It's very hard in this world to think that people are diminishing you because you play a vain, kind of goofy character, so to speak," he continues. "If that's how you're going to look at Ashton, then you're probably going to think that I came in second place at the U.S. Open based on 'Tin Cup.' "

Being Jake

More than anything, what's striking about Kutcher is how at ease he is, how little outside perceptions affect him. He's funny and self-deprecating and wholly realistic.

"Look, it was a stretch," he says of the decision to cast him. "I know that. I think that's uncomfortable for anyone."

Part of the stretch was the physical nature of the role. In order to be believable as a top-notch swimmer, Kutcher put himself through eight months of personal boot camp, adding more than 10 pounds of muscle to his frame and swimming laps weighted down with heavy equipment. He also gave up smoking.