: Many, if not most, people actively disdain common sense, practicality, realism, and accuracy because they don't want to have the emotions their swept up in to be dashed. Then once real life shows up and dashes them for them as a matter of course they disdain common sense, practicality, realism, and accuracy because they don't want to feel and to admit to themselves but especially to others that they're stupid.
@Pennyformythoughts: Often it isn't they they don't know... well, that they don't *think* they know. Because they're blinded by their desire to do whatever it is. In the face of any manner of prodding them to think about it they circle the wagons, and their egos do a protecc, as egos do.