Certainly for my father, there were great times, good times, not-so-good times. He might be shooting a Fellini film for six months, then not working for two months. I'm used to that dynamic.

I know, for a fact, that I'm a very different person on my own than I am with someone else. We are different with each other. These things are constantly adjusted. And that's true of humans. That's not just true of famous people.

I was a fan of Hitchcock, but more importantly than that, he is such an inscrutable man, and a very carefully inscrutable man. He apparently was blank-faced with a calm and controlled presence. I was immediately anxious and thought, 'How am I going to get behind that?'

I get plenty of time to re-engage with the world I'm trying to depict, so I'm not always living in these parallel worlds.

There are things that I would avoid, so I have the choice to say no, when I feel I'm repeating myself too much. But then there could be a reason to do that with a good director. So I think actors have to have a loose philosophy.

I don't know if it's harder but when you're playing a real person you want to honor their memory - even if they're a criminal or someone that the public loathed. That can be challenging.

I teach for the Book Trust, which promotes reading and writing with children.