Family holidays and weekends are really brightly colored memories, full of my mother and father, rather than our nannies and au pairs.

I'm a mixture of Anglo-Saxon, a bit of Spanish and one-eighth American. I've often wondered if I have an Asiatic ancestor from the East as well because I have deep-set eyes. Make-up artists are constantly trying to shade my eyelids, and I have to point out that I don't have any!

I'm not much of a Method actress, so even though my character in The Ghost Writer was quite dark and bad-tempered, I could only do that if I was seeming quite perky.

My husband Rhashan reminds me of my father because he's got great strength of character.

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 had the best teacher in the business. Kevin Costner was my teacher. I was acting opposite him and he was directing me. The way he directed me, for which I am eternally grateful, is he would watch the scene back on the monitor, which is sort of considered unfashionable - you're not meant to watch yourself. But he was like, "Come around. Watch this. See there, you're doing a great reaction, but you're doing it out of frame." That was exactly what I needed. I learned how to act on film from him.

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