Quote from : The Hitchhiker's Guide to the Galaxy Book

One of the things Ford Prefect had always found hardest to understand about human beings was their habit of continually stating and repeating the very very obvious, as in or or At first Ford had formed a theory to account for this strange behaviour. If human beings don't keep exercising their lips, he thought, their mouths probably seize up. After a few months' consideration and observation he abandoned this theory in favour of a new one. If they don't keep on exercising their lips, he thought, their brains start working.