When you're training as an actor, a lot of the big work you're learning is to treat fictional characters like real people. You don't have the problem of discovering a backstory with real people, but there's always a mystery which is common to both fictional and factual characters. They are never quite the person you think they are.

The prosthetics were interesting because the artist was so good that they could just put a Hitchcock mask on me, but you don't want to do that. You're an actor playing Hitchcock, so it's about how much of that you're going to do.

I had to change the shape of my own voice. It was quite hard to pull off and so once I had it, I stayed in Hitchcock's voice all day on set.

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 work best when a little scared, when there's so much more than the lines to think about.

Best ever was filming in Barcelona last year, and I had a couple of scenes with De Niro. He's a very shy man. Speaks so quietly that people tend to bend down and adopt the same tone, almost the same voice, whenever they talk to him - watching, you'd think someone's offering to carry out a hit for him when they're just offering him a cup of coffee.

The script for 'Infamous' was so poised between tragedy and comedy. It's a dream part. One reads those scripts with a sense of melancholia. When you read a script that good I remember thinking, 'Oh, this script is too good. They'll never give it to me.'