Les Annales du Disque-Monde, Tome 13 : Les Petits dieux (1992)

He knew from experience that true and obvious ideas, such as the ineffable wisdom and judgment of the Great God Om, seemed so obscure to many people that you actually have to kill them before they saw the error of their ways.

Om began to feel the acute depression that steals over every realist in the presence of an optimist.

Fear is a strange soil. Mainly it grows obedience like corn, which grows in rows and makes weeding easy. But sometimes it grows the potatoes of defiance, which flourish underground.

And it all meant this: that there are hardly any excesses of the most crazed psychopath that cannot be easily duplicated by a normal, kindly family man who just comes to work every day and has a job to do.

"Life in this world," he said, "is, as it were, a sojourn in a cave. What can we know of reality? For all we see of the true nature of existence is, shall we say, no more than bewildering and amusing shadows cast upon the inner wall of the cave by the unseen blinding light of absolute truth, from which we may or may not deduce some glimmer of veracity, and we as troglodyte seekers of wisdom can only lift our voices to the unseen and say, humbly, `Go on, do Deformed Rabbit . . . it's my favorite.' "

People have reality-dampers.
It is a popular fact that nine-tenths of the brain is not used and, like most popular facts, it is wrong. Not even the most stupid Creator would go to the trouble of making the human head carry around several pounds of unnecessary gray goo if its only real purpose was, for example, to serve as a delicacy for certain remote tribesmen in unexplored valleys. It is used. And one of its functions is to make the miraculous seem ordinary and turn the unusual into the usual.
Because if this was not the case, then human beings, faced with the daily wondrousness of everything, would go around wearing big stupid grins, similar to those worn by certain remote tribesmen who occasionally get raided by the authorities and have the contents of their plastic greenhouses very seriously inspected. They'd say "Wow!" a lot. And no one would do much work.
Gods don't like people not doing much work. People who aren't busy all the time might start to think.
Part of the brain exists to stop this happening. It is very efficient. It can make people experience boredom in the middle of marvels.