I never talk about 'Harry Potter' because I think that would rob children of something that's private to them. I think too many things get explained, so I hate talking about it.
I've learned, having been on a lot of sets, the good news is that by definition you are surrounded by experts. They get fired if they're not - unlike in the theatre!
I approach every part I'm asked to do and decide to do from exactly the same angle: who is this person, what does he want, how does he attempt to get it, and what happens to him when he doesn't get it, or if he does?
Snow Cake is a lovely film. Really proud of that. We shot it in 21 days. I thought Sigourney was amazing in it. And very, very accurate. I think there was some element that thought she had pushed it too far. But not at all when you do the amount of homework she had done and spent the amount of time she did with adult autistics. She was right on the money. And I think Marc Evans is a terrific director. He's a sweet, open, honest man and a really good director of actors.
I'm very aware that when one is acting in the theater, you do become kind of animal about it. And you're reliant on instincts rather than tact a lot of the time.