This planet has—or rather had—a problem, which was this: most of the people
living on it were unhappy for pretty much of the time. Many solutions were
suggested for this problem, but most of these were largely concerned with the
movements of small green pieces of paper, which is odd because on the whole it
wasn’t the small green pieces of paper that were unhappy.
[...] Many were increasingly of the opinion that they’d all made a big mistake
in coming down from the trees in the first place. And some said that even the
trees had been a bad move, and that no one should ever have left the oceans.