I remember in 'Pride and Prejudice' I had to do a scene where I broke down. And before we filmed I spent like three hours imagining my mum's funeral. Actually, she's very much alive, happy and healthy. It was really horrible.

When you start playing a character every day for seven weeks, it suddenly starts becoming easier.

When I went to the Oscars - the only time I've ever been to the Oscars - a few years ago, I wore this Prada dress covered in cooking utensils. I got drunk at the end of the night and started ripping them off and giving them as presents to people, so that was fun. I'm pretty sure that was the point of it, that's how Miuccia meant for it to go I'm sure.

I've always played characters that were younger than myself.

It makes it easier, if you can't do an American accent. I don't know. It's different. I played a character in Never Let Me Go where the script for my character was very sparse, and I enjoyed it. With Never Let Me Go, I had a whole book written from my character's point of view, so I always knew where I was. But, with Ryan [Gosling], it was just easy. He's such a brilliant actor and he is so prepared. He doesn't have to warm himself up to be in a scene. He's just in it. It draws you in, in a way.

Leonardo is the most incredible actor, on the planet, with a couple of people alongside him. Getting to act with him is just [amazing]. I walked away from my audition for that and I couldn't believe that I'd been acting with him. I've worked with amazing people, but my friends freak out that I'm working with him. I freak out in a geeky acting way. They freak out in a starstruck way. He's Leonardo DiCaprio, and his fame is so big. That's a complete tangent about that.

Sex addiction is a subject that should be discussed