One of the major problems encountered in time travel is not that of accidentally becoming your own father or mother. There is no problem involved in becoming your own father or mother that a broadminded and well-adjusted family can't cope with.

Arthur shook his head and sat down. He looked up. “I thought you must be dead …” he said simply. “So did I for a while,” said Ford, “and then I decided I was a lemon for a couple of weeks. I kept myself amused all that time jumping in and out of a gin and tonic.

Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.

This man is the bee's knees, Arthur, he is the wasp's nipples. He is, I would go so far as to say, the entire set of erogenous zones of every major flying insect of the Western world.

Why should I want to make anything up? Life's bad enough as it is without wanting to invent any more of it.

Protect me from knowing what I don't need to know. Protect me from even knowing that there are things to know that I don't know. Protect me from knowing that I decided not to know about the things that I decided not to know about. Amen. [...] Lord, lord, lord. Protect me from the consequences of the above prayer.

Very strange people, physicists - in my experience the ones who aren't dead are in some way very ill.