Writing for adults often means just increasing the swearing - but find an alternative to swearing and you've probably got a better line.

You don't want to take over the universe. You wouldn't know what to do with it beyond shout at it.

Hitler: Thank you, whoever you are. I think you just saved my life. The Doctor: Believe me... It was an accident.

Like most writers, I write about what has happened to me as that involves the minimum amount of research.

Don't play games with me! You just killed someone I like, that is not a safe place to stand! I'm the Doctor, and you're in the biggest library in the Universe. Look me up.

Well, the world is vastly counted in favour of men at every level - except if you live in a civilised country and you’re sort of educated and middle-class, because then you’re almost certainly junior in your relationship and in a state of permanent, crippled apology. Your preferences are routinely mocked. There’s a huge, unfortunate lack of respect for anything male.

The story of Sherlock Holmes, on the surface, is about detection, but in reality, it's about the best of two men who save each other - a lost, washed-up war hero and a man who could end up committing murders instead of solving them. They come together. They become this perfect unit. They become the best friendship ever, and they become heroes. That's what we fall in love with, not Sherlock on his own. No one can love that man on his own, but Sherlock Holmes and Dr. Watson - the best friends ever.