Inspiration Particles
Inspiration Particles sleet through the universe, each heralding a moment of brilliance: a new symphony, a way of getting from A to B quicker than before, lines for a new play, or deeper understanding of something than was previously comprehended.
Most of them are doomed to miss, or to reveal their brilliance to a brick wall or a starling, which is totally unequipped to deal with the revelation.
Some however, hit the right mind at the right time, and a little later you are blinking foolishly in the TV lights and wondering how the hell you thought of sliced bread in the first place...
Many of these particles hit Leonard of Quirm, one of whose first inventions was a metal helmet designed to keep them out as he was accustomed to the embarrassment of waking to find he had nocturnally scribbled all over his bedsheets.
There was a famous incident in Sourcery, when Rincewind was hit by one of these particles. What came out of his mouth wasn't his and would have made sense to many a learned Wizard. However, it was said to Conina and Nijel, whereat Conina called him an idiot. Such is the lot of the inspired...
In the collection of Terry's children's writings, Dragons At Crumbling Castle, there is a short story - dating from 1966 - called Dok the Caveman. This tale concerns a single prehistoric man, the eponymous Dok, who manages to single-handedly invent everything we speculate originated in prehistory. All at once. Language, the wheel, fire, animal husbandry, weaving.... Dok then inflicts them all on a pre-history not yet ready to receive such advanced thinking. It is as if every inspiration particle hit him all at once...