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

Young Reinette: Monsieur, be careful! The Doctor: It's just a nightmare, Reinette, don't worry, everyone has nightmares. Even monsters under the bed have nightmares! Young Reinette: What do monsters have nightmares about? The Doctor: Me!

The Doctor: Oh, now what's this, then? I love this. A big, flashy-lighty thing. That's what brought me here. Big, flashy-lighty things have got me written all over them. Not actually, but give me time... and a crayon.

The Doctor...is embarrassingly human for an alien.

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

What's the point of being a grown-up if you don't get to be immature?

You have to take your own bold approach, and if you do you will be rewarded with success. Or calamitous failure. That can happen too.