It's a fez. I wear a fez now. Fezes are cool.

Madame Kovarian: The anger of a good man is not a problem. Good men have too many rules. The Doctor: Good men don't need rules. Today is not the day to find out why I have so many.

I always rip out the last page of a book. Then it doesn't have to end. I hate endings!

Sherlock Holmes becomes more human and more adept at fitting in with a lot of people, but he remains separate from the human race because he finds that a better place to observe that from. He stays on the mountain top because there, he can see clearly.

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

River Song: Right, I have questions. But number one is this: what in the name of sanity have you got on your head? The Doctor: It's a fez. I wear a fez now. Fezzes are cool.

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