When I was young, there weren't any teenage girls I could relate to in film. They were all put in boxes: the virginal good girl, the really sarcastic asexual one. I wanted to do something that represented how I felt then.

'Diary of a Teenage Girl' was my first American movie. It was my first movie in an American accent. It's based on a graphic novel, which was written in 2002 by someone called Phoebe Gloeckner. It was turned into a play by Marielle Heller, who then wrote it as a screenplay for Sundance Labs.

Jack Thorne writes so well for messed-up teenage girls.

I find teenage girls endlessly funny.

It sounds so negative of me to say, but I don't feel like there were many coming-of-age films when I was growing up. I think that when I was a teenager, I felt really misrepresented in the teenage roles that I was watching onscreen. Especially in women.

I have this dream that secretly all teenage girls feel exactly like me. And maybe one day, when we all realize that we all feel the same, we can all stop pretending to be something we're not.