Everything about filmmaking is incredibly weird, and there's nothing natural about watching yourself on the big screen or hearing your voice. It's that same thing that you feel when you watch yourself on a video camera and you hate the sound of your voice - it's that times 800.

It's the weird thing Eton does - you're at school next to lords and earls and, in my case, Prince William, so you end up being used to dealing with those sorts of people.

I find that what doubt does, or fear, is it makes you come up with as many ideas as you possibly can. And on film that works 'cause you're then handing over that fear to the director, who has to make sense of all those options!

I love the variety of films. In theater, you go into a room and the director runs the room, so you all work to his or her method. On film, if an actor or an actress is in for a day or two, the director has to get out of that actor what they need, so they have to change and adapt to that actor's technique.

I'm as voyeuristic and intrigued as the next person as to how celebrities live.

I feel like J.K. Rowling's world is one that is owned by everyone in some ways. People have grown up with it and have such a sense of that universe that there's something kind of wonderful seeing everyone get involved.

Ladies and babies, and mortgages, for that matter, can all wait. Acting has done a strange thing to me, though. I often sit there, thinking, 'I love this, but I wouldn't put my daughter on the stage.'