When I was young I became kind of a party animal. I had a massive crash. My health suffered. I was just overdoing it. That person could not be further from the one who emerged from that earlier experience. I regressed massively.

I had a very sparse comic upbringing - not because I was being whipped into reading Chekhov and Dickens, but I read Asterix on holidays when I was a kid, and Tin Tin was featured, I remember, for a few years.

I've gone up two suit sizes. The character I'm playing, he's strong, I can say that much. I've changed my physique a bit, so that requires eating like a foie gras goose, well beyond your appetite. Providing I don't feel too ill, I then work out two hours a day with a phenomenal trainer. It's the L.A. way.

Even in cerebral roles that are seemingly intelligent and nothing else, I think it's so important to wrap your characterization in a physical form as well.

Sherlock being the most prevalent, and they've been really good fun.

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.

I ate healthily, but there was no snacking, no drinking, no bread, no sugar, no smoking. Afterwards I had a pork belly roast.