Everything about filmmaking is incredibly weird, and there's nothing natural about watching yourself on the big screen or hearing your voice. It's that same thing that you feel when you watch yourself on a video camera and you hate the sound of your voice - it's that times 800.

As a runner on a film, you are the lowest of the low, and yet you have incredible access to everyone. I can totally imagine that for actors in the middle of a Hollywood bubble, all they really want is a sense of normality, and that gopher can be a tap for that.

Making 'Birdsong,' on the one hand you have how prestigious it is and the reputation of the book, which is something that's an extraordinary piece of work. Sebastian Faulkes is a genius. So you feel that responsibility when you're portraying that character that he's imagined and millions of readers have pictured.

It's the weird thing Eton does - you're at school next to lords and earls and, in my case, Prince William, so you end up being used to dealing with those sorts of people.

I love the variety of films. In theater, you go into a room and the director runs the room, so you all work to his or her method. On film, if an actor or an actress is in for a day or two, the director has to get out of that actor what they need, so they have to change and adapt to that actor's technique.

I think all actors have a similar deal. You want some people who understand. Although it looks great - and is great - there are also shoddy moments when you feel really rotten, and when it's going well, you're not allowed to complain.

I always try to describe making movies like summer camp, or some holiday where you spend all day, every day with a new group of people whom you kind of love and then never see again.