I think it would be self-indulgent to go, "Oh, I'm going to make this character different by giving him a quirk of some kind." I don't think that serves the story, particularly. But even very similar scenes with a different set of actors, a different set of circumstances, it starts to evolve as a different character.

I mean, you know, while I'm acting on stage I'm ranking quite high, but in a room with Barack Obama I'm probably into negative digits. I never feel very famous.

I'm quite happy to leave it still feeling that way, leave it before it starts feeling like a job. ... I have such fond memories of watching 'Doctor Who' when I was a kid and growing up, that if I've left anybody anywhere with memories as fond, then I feel like I've done my job.

I was always going to act, literally ever since I was tiny. In fact, I have Doctor Who to thank for that. I wanted to become an actor after being obsessed with Tom Baker, the fourth Doctor Who, in the 1970s. His was the definitive performance of all time in anything.

And the very fact of how you speak somehow influences who you are. The way you move, the way you think, it seeps into your being, and it's quite hard to really break that down entirely.

I love characters who are clever and smart, and you have to run to catch up with. I think there's something very appealing and rather heroic in that.

I've always been a geek and slightly awkward… slightly umm… I was never the cool kid at school.