Fallacy: a deceptive, misleading, or false notion, belief, etc.; any of various types of erroneous reasoning that render arguments logically unsound.
It seems as if many of us that live on top of this majestic, rotating mud-ball tend to live through fallacies. Plenty of us take on beliefs that are theoretically sound and, at the same time, realistically silly. Others believe in things that aren’t worth wiping one’s backside with.