Rose: 'If you are an alien, how come you sound like you're from the north?' Doctor: 'Lots of planets have a north!

When man invented fire, he didn't say, "Hey, let's cook." He said, "Great, now we can see naked bottoms in the dark.

Being the only writer on a successful show is very rewarding.

Fascinatingly confident, rude people are great.

Nothing can ever be a rule in drama, because then you're saying certain things won't ever happen, and that would be very boring.

When you're surrounded by friends and exes, there's a whole lot of stuff that starts crawling out. But however serious and traumatic those experiences may be to the participant, to the onlooker they're hilarious.

The Doctor: I've seen bigger. Clara: Really? The Doctor: Are you joking? It's massive!