"“In stories, where the genie or the magic frog or the fairy godmother gives you three wishes…what’s the third wish?” “Ah, stories,” said Granny. “That’s easy. In any story worth the tellin’, that knows about the way of the world, the third wish is the one that undoes the harm the first two wishes caused.”"
January 1, 1970
https://en.wikiquote.org/wiki/Discworld