The trouble with a series as it gets older is it can feel like a tradition, and tradition is the enemy of suspense, and it's the enemy of comedy. It's the enemy of everything, really. So you have to shake it up.

I don't want to think that the stories are finite; I want to feel that they can go on forever.

See the bowtie? I wear it and I don't care. That's why it's cool.

When writing comedy, you have to have the confidence to believe that there is only one type of relationship in the world, and we are all having it, that all men behave in the same way and so do all women.

Every episode [in a TV series] is a challenge, and what's challenging in most episodes is the monster. You're always a heartbeat from the monster looking ridiculous. You really have to work so hard to make them not look like ridiculous when they turn up on the set.

I like that Helen Mirren has been saying the next doctor should be a woman. I would like to go on record and say that the Queen should be played by a man!

Madness is just what a genius looks like to a tiny mind.