Well, I needed the work - that's the honest answer. I haven't worked for a while, a couple of years. So I thought it would be nice to get back to work and earn some money.

By the way, the Harry Potter series is literature, in spite of what some people might say. The way J.K. Rowling worked that world out is quite something.

I got obsessed with classical music, I got obsessed with Chopin, with playing the piano.

Rather like Batman, I embody the themes of the movie which are the values of family, courage and compassion and a sense of right and wrong, good and bad and justice.

And of course I've got kids of my own now, and they love me being in the Harry Potter films. I'm now part of a phenomenon. You become incredibly cool to your kids, and you get a young fan base. So you became the cool dad at school. You're suddenly hip.

People have an idea that one is in control of a career, a lot more than you really are. You can engineer things to an extent. But you are at the mercy of what comes in across the desk.

If one could have a wish, or an alternative life, I would've liked to have been John Lennon.