Most people think most people are just like them. This causes plenty of problems, all unique to the traits you think everyone else possesses. Next time you find yourself wondering why on earth someone would do something that baffles you, try to think of the ways they might be different to you, because they probably are.
Mokalus of Borg
PS - For instance, I tend to think most people think very logically and literally.
PPS - And I make that mistake a lot, even when I try not to.