I don't mind doing the whole red carpet thing when I have to when it comes to publicizing a movie. But besides that, I don't like those kinds of things at all. Celebrity status is not really something that appeals to me.

When I can't get the character out of my head, and I'm in my bedroom and I start to actually act out the scenes that I've read in a script, I think okay, I really want to do this.

I've basically grown up with Harry Potter, as so many kids my age have. It's kind of a part of my life.

I remember being on Atonement and it felt very right to be there. There was so much excitement every day. I remember very vividly how it felt to be a child on a film set, and that is actually really important to hold on to for as long as you continue to make films.

I like my characters to be ones I think about long after I've finished reading the script.

We've done a lot of films now about the IRA, we can move on from all that. I loved '71 because I think it showed a very honest trail and what it was actually like. It wasn't one-sided. I really respect ['71 director] Yann [Demange] for what he did. But we have done a lot of those things.

One of the things that would steer me away from a franchise is that I'm playing the same character all the time and I wouldn't want to be known for that.