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 do get stopped a bit now and then, but I can go to the supermarket and on the Tube without being noticed. It's usually me that gets starstruck, especially by TV stars.

They're such hierarchical things, film sets, they're sort of mini societies. Often they're incredibly political places.

I'm quite ignorant about fashion and I'm colourblind, so it's all a tad tricky. My only knowledge of that world comes through Christopher Bailey, whom I first met in 2008 when I did a campaign for Burberry that featured musicians, artists, actors and sportsmen.

And you can't complain about kissing Emma Watson. Isn't that what everyone in the world wants to do? I've known Emma for a few years. She's this amazing capacity of young and vibrant and brilliant, but also a bright, intelligent old soul.

My first film, 'Like Minds,' was with Toni Colette, who was extraordinary. I mean it was basically a mini-masterclass for acting on film at a time when all you could probably see were my eyebrows bouncing up and down on screen.

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.