There was one planet off in the seventh dimension that got used as a ball in a game of intergalactic bar billiards. Got potted straight into a black hole.

I've come up with a set of rules that describe our reactions to technologies: 1. Anything that is in the world when you’re born is normal and ordinary and is just a natural part of the way the world works. 2. Anything that's invented between when you’re fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it. 3. Anything invented after you're thirty-five is against the natural order of things.

It is a well-known fact that those people who must want to rule people are, ipso facto, those least suited to do it... anyone who is capable of getting themselves made President should on no account be allowed to do the job.

Dirk turned on the car wipers, which grumbled because they didn't have quite enough rain to wipe away, so he turned them off again. Rain quickly speckled the windscreen. He turned on the wipers again, but they still refused to feel that the exercise was worthwhile, and scraped and squeaked in protest.

Trillian had come to suspect that the main reason [Zaphood] had had such a wild and successful life was that he never really understood the significance of anything he did.

I come in peace...Take me to your lizard.

Yes, it is true that sometimes unusually intelligent and sensitive children can appear to be stupid. But stupid children can sometimes appear to be stupid as well. I think that's something you might have to consider.