Oscar champ Russell Crowe confesses that playing real-life Nobel Prize-winning scientist John Nash in A Beautiful Mind was a bigger challenge than he anticipated. At least when he portrayed tobacco industry whistle blower Jeffrey Wigand in 1999's The Insider he had something to model his performance after. "I spent hours watching tapes of Wigand," he tells TV Guide Online, "but there was not a single piece of film — not even an audio tape — of Nash as a young man."

So, how did Crowe get inside the head of the schizophrenic Princeton mathematician? Well, he let his nails grow, natch. "I have little sausage stumps of fingers, but I'd noticed in a photo that Nash had these graceful hands with tapered fingers," he says. "I decided having longer fingernails would sort of help that image. In fact, the day after I won the Oscar for Gladiator I was in New York getting a manicure [for] A Beautiful Mind."

Even though Nash is still alive, Crowe admits he resisted the temptation to meet his esteemed alter ego face-to-face — at least initially. [Nash eventually dropped by the set.] "He's in his 70s, and for most of the movie I play him as a much younger man," he says. "I sent him a list of questions to which he replied on videotape. But I was always a little cautious about what he might be remembering about his early life. For instance, he says he never smoked cigarettes and I know he did."

As for acting out the agonizing schizophrenia that got Nash committed to a mental institution, Crowe says, "I know there are cheap jokes about actors having split personalities, but... schizophrenia is nothing to make fun of — even if Jim Carrey did it in Me, Myself and Irene. I'm not taking anything away from his very funny performance, [but] it's a very insidious and debilitating condition."

If you believe the tabloids, Crowe himself is battling what some might consider an insidious condition. "My reputation as a wild sexual beast or whatever is pure media-manufactured bull [expletive]," he groans. "I've always taken my job — but not myself — seriously. I'm not going to play a real-life role that somebody has manufactured. [Expletive] that! If my salary tumbles and my choices of roles are limited by that, who cares. I'm only going to be happy if I'm happy with myself."