Kathy Nightingale: What's good about sad? Sally Sparrow: It's happy for deep people.

Witty and mean is easy - but fond and funny is hard.

I can't see what's wrong about assuming intelligence in your audience and what's bad news about being rewarded for assuming that.

I think training in comedy, as it were, a history writing comedy, is a powerful tool for anyone.

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

Amy: I had something I wanted to tell him. Stuff always gets in the way. Canton: Stuff does that.

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.