Believe me, it is a great deal better to find cast-iron proof that you're innocent than to languish in a cell hoping that the police---who already think you're guilty---will find it for you.

I am rarely happier than when spending an entire day programming my computer.

The lights were off so that his heads could avoid looking at each other because neither of them was currently a particular engaging sight, nor had they been since he had made the error of looking into his soul. It had indeed been an error. It had been late one night-- of course. It had been a difficult day-- of course. There had been soulful music playing on the ship's sound system-- of course. And he had, of course, been slightly drunk. In other words, all the usual conditions that bring on a bout of soul searching had applied, but it had, nevertheless, clearly been an error.

Everything you see or hear or experience in any way at all is specific to you. You create a universe by perceiving it, so everything in the universe you perceive is specific to you.

Zaphod did not want to tangle with them and, deciding that just as discretion is the better part of valor, so was cowardice is the better part of discretion, he valiantly hid himself in a closet.

They live in perpetual fear of the time they call "The Coming of the Great White Handkerchief

All you really need to know for the moment is that the universe is a lot more complicated than you might think, even if you start from a position of thinking it's pretty damn complicated in the first place.