Most people can grasp the concept of a slope or a lever. But they would not be able to construct a water pump. So when the well is too tiresome or inefficient they turn to a specialist to help them solve their problem. If, after a certain while that specialist tells them to not waste the water they now so easily access because the well might run dry, they will not listen because as everyone can clearly see – you move the pump, the water flows, he obviously does not know what he is talking about. Now that is really disturbing.
Take that concept a step further. Belief is the biggest enemy of knowledge.