As an actor, you're just taking temperature. I am anyway, all the time, and responding appropriately. I was again cast very last-minute for Rushmore and met Wes Anderson, this quite physically and socially awkward man who didn't really talk to me much, a precocious and intelligent young boy. And Bill Murray. And we were sort of left in this bizarre hotel together and taken to strange locations around Houston. That was quite an isolating experience.

I thought "I've coped with some crazy situations, and I can do this." But working with Roman Polanski is so different from the fashionable and accepted way of directing now.

Working with Roman Polanski is funny. It's like anything in life - someone warns you that something's going to be amazing or difficult or awful, and you say, "I can do that. I can cope with that." And then when you're in the middle of it, it may be joyful or tricky, but it's never difficult in the way you think it's going to be difficult.

That was a bizarre and unlikely event, which has misled a generation of drama students from my old drama school that dreams really do come true. I was an unemployed actor. I had been an actor for about eight years, and had worked in theater, and done a tiny bit of TV, and somehow an audition video of mine ended up on Kevin Costner's television screen, and he rang me up and invited me to fly first-class to Hollywood and be in his movie The Postman.

For me, selfishly, The Postman didn't kill my career. It meant I didn't shoot straight and painfully into the limelight, but Rushmore came out of it. No one would have known where I was to cast me in Rushmore had I not been in The Postman. Because they shared a producer. Nor would I have been in The Sixth Sense. Nor would I be speaking to you now if Kevin Costner hadn't cast me in The Postman.

My parents taught me everything and set me up for life. I owe to them all the things I'm passionate about: music, art, the people I love, my career and family life, the fact that I have children and the way that I raise them.

I'm on record as having said "I've done this amazing movie - The Sixth Sense - that no one is going to see." And then it stayed in the top 10 American films for about six months. So don't ask me. I'm the most disastrous PR and marketing predictor.