[Sherlock Holmes] has moved from being someone who was sociopathic, work-obsessed and slightly amoral, into being someone who has a certain degree of a private life, which is very, very private, with The Woman, or Irene Adler.

It still makes me giggle that I'm paid to act.

Laughing and crying are really similar - what happens to your body. It's a very similar process in your diaphragm. Like a musician, you have to do your scales once in a while and warm up your voice.

I was brought up in a world of privilege.

You can perfect genius because genius is not perfection. On his level and his practice and his methodology, it's almost inhuman. So, that's been a fantastic arc to play, and boy does it go somewhere in this series.

I've been very lucky at what's happened in my career to date, but playing something as far from me as possible is an ambition of mine - anything from a mutated baddy in a comic book action thriller, to a detective. If anything, I'd like Gary Oldman's career: he's the perfect example of it. I've love to have a really broad sweep of characters - to be able to do something edgy, surprising and unfashionable.

My massive motivation in life is to make parents proud. But even that has to stop at a point.