I have many debates now with friends on the changes, and the continuing confusion over bringing up your children, instilling values, letting them make the right choices.

If the role is right and it's another situation of having a benevolent genius at the head of it, someone who likes actors, and will protect the actors from the ravages of reality-TV drama. It's a brutal world, and you need to have a strong creative team who can stand up to the network.

The phrase you usually hear after a cut is "That was great. Perhaps we could have another go. Maybe try it this way." Even that much direction is prefaced with a lot of praise and encouragement. It's quite like how you deal with toddlers: positive reinforcement, and then a little suggestion that you might want to try something different. Roman Polanski will stop the take and shout, "No, no, no!" Which is somewhat alarming the first time it happens.

Usually the casting process is lengthy and humiliating, but in this instance, The Ghost Writer, it was just too easy. I was sitting in a rental car on an L.A. street and my cell phone rang, and it was Roman Polanski on the line. I couldn't really believe my luck. He said, "See you in Berlin." I sat staring at a palm tree, thinking how surreal that was.

When Roman Polanski did give you a "Great, great, great!" you were just like, "Thank you, Lord, for this magical moment."

That was a bizarre and unlikely event, which has misled a generation of drama students from my old drama school that dreams really do come true. I was an unemployed actor. I had been an actor for about eight years, and had worked in theater, and done a tiny bit of TV, and somehow an audition video of mine ended up on Kevin Costner's television screen, and he rang me up and invited me to fly first-class to Hollywood and be in his movie The Postman.

I didn't know box office was a thing you could possess but I don't have it. I go up for lovely roles and people with this nebulous thing called box office get them so there isn't much I can do about that unless you know where I can get some box-office myself!