Particles of raw inspiration sleet through the universe all the time. Every once in a while one of them hits a receptive mind, which then invents DNA or the flute sonata form or a way of making light bulbs wear out in half the time. But most of them miss. Most people go through their lives without being hit by even one.

Wyrd Sisters: (Discworld Novel 6) (ed. Random House, 2008) - ISBN: 9781407034621