The point is, you see," said Ford, "that there is no point in driving yourself mad trying to stop yourself going mad. You might just as well give in and save your sanity for later.

Zaphod felt he was teetering on the edge of madness and wondered if he shouldn't just jump over and have done with it.

What sane person could live in this world and not be crazy?

I guess when you turn off the main road, you have to be prepared to see some funny houses.

The statistics on sanity are that one out of every four Americans is suffering from some form of mental illness. Think of your three best friends. If they're okay, then it's you.

Every madman thinks all other men mad.