Whats fascinating is that when you write a script, its almost a stream of consciousness. You have an idea that it means something, but youre not always sure what. Then when you get on the set, the actors teach you.

I have three kids who like Harry Potter so I was sort of aware of it. You can't really move from it: it's on buses, in stores, it's everywhere. One of my kids has read the books; the other two are too small but they like the movies.

I don't go to premieres. I don't go to parties. I don't covet the Oscar. I don't want any of that. I don't go out. I just have dinner at home every night with my kids. Being famous, that's a whole other career. And I haven't got any energy for it.

The great thing about having been in a lot of make-up, and stuff like that, is that when you're working with someone who's in it, and you've been there and done it, but you're not in it anymore, you feel so good.

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.

I still don't have a publicist. If I'm in a film, you have an obligation to promote it, I'll do as much as I can.

Sometimes directors feel like they have to justify that hat that they are wearing they've got on as a director, and they come in and they tweak and interfere.