No. I don't like the idea of prodding people. There are lots of other ways to get that sort of information without invading people's privacy. Especially for somebody like me, who spends so much time telling people to f--- off and get out of my life. Research is about observation, not about, you know, sticking your fingers in people's navels.

But you did meet with the real Nash?

Not at first. I had him answer specific questions on videotape. I didn't want to pressure Nash by sitting directly in front of him -- not because of any reputation I have, but just because I'm the guy playing him. But eventually he came on the set and we met. I asked him one simple question, which he took 15 minutes to answer.

What was the question?

Whether he wanted a cup of coffee or a cup of tea. We ended up using part of his answer in the film. There's a scene where someone asks me if I want a cup of tea and I start muttering about how I don't know what kind of tea they serve, whether or not it would be suitable for my palate, if it had the density of flavor that appeals to me.