What I mean is that if you really want to understand something, the best way is to try and explain it to someone else. That forces you to sort it out in your mind. And the more slow and dim-witted your pupil, the more you have to break things down into more and more simple ideas. And that's really the essence of programming. By the time you've sorted out a complicated idea into little steps that even a stupid machine can deal with, you've learned something about it yourself... The teacher usually learns more than the pupils. Isn't that true?

The Saab seethed off into the night. Arthur watched it go, as stunned as a man might be who, having believed himself to be totally blind for five years, suddenly discovers that he had merely been wearing too large a hat.

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.

You just come along with me and have a good time. The Galaxy's a fun place. You'll need to have this fish in your ear.

Reality is hopelessly inaccurate.

It's good to leave your room super-messy when you're away. Whoever tries to break into your room will thought it has already been ransacked.

The party and the Krikkit warship looked, in their writhings, a little like two ducks, one of which is trying to make a third duck inside the second duck, whilst the second duck is trying very hard to explain that it doesn't feel ready for a third duck right now, is uncertain that it would want any putative third duck anyway, and certainly not whilst it, the second duck, was busy flying.