My character in HIM is a fairly typical teenager from a broken family. It's a time of life that I remember well - obviously, I'm only 19 - but a lot of stuff happens when you're that age. You have people treating you like a boy but expecting you to behave like a man. The awkwardness is a big one that I identify with. I'm still quite awkward now really.

My Dunkirk co-star Harry Styles deals with some crazy fan stuff, but he's a very down-to-earth, lovely, funny guy. I think you can overthink dealing with fame. To an extent you've got to put yourself out there, but I feel like your work should really speak for itself and I don't feel the need to go and make everyone like me because, to be honest, I'm not looking to be friends with the world. I'd much rather people watch the things that I'm in.

I don't really think much about how I would have fared in the Second World War. It's a topic that has to be treated with respect and subtlety and you can't just go in all guns blazing and make an epic action film. In the current political climate it seems like people are forgetting, but hopefully they can look back and realize what a mistake we all made as opposed to thinking, "Oh yeah, I'd be fine in there!"