Only simple ideas can be held by large groups of people. Commonly held ideas are almost always dumbed down until they are practically lies... and often dangerous ones. Once vast numbers of people have come to believe the lie, they adjust their own behavior to bring themselves into sync with it, and thereby change the world itself. The world, then, no longer resembles the one that gave rise to the original insight. Soon, a person's situation is so at odds with the world as it really is that a crisis develops, and he or she must seek a new metaphor for explanation and guidance.