[on BBC's Sherlock] It's a rare challenge, both for the audience and an actor, to take part in something with this level of intelligence and wit. You have to really enjoy it. It's a form of mental and physical gymnastics.

I am very flattered. I have also become a verb as in "I have cumberbatched the UK audience" apparently. Who knows, by the end of the year I might become a swear word too! It's crazy and fun and very flattering.

I'm always playing characters with intellects profoundly superior to mine. That's great fun, even though it's as much a fantasy for me as for the people watching me.

I have memories of clouds whisking by while sitting in the pushchair on the roof of my parents' flat. I loved it! I just loved staring at the clouds and dreaming away.

Only when Stephen Strange has his accident and everything that he's ever had in his life falls apart that he becomes pretty monstrous. It's the self-loathing rage of a wounded animal and he doesn't have a coping mechanism at all. It ties in with the discipline and the magic of this world.

I drag a lot of stuff round with me that I don't need.

Conan Doyle is amazing in the way he has Watson describe Sherlock’s posture, mood swings, his hand gestures, and so forth in the novels.