Pessimism is often a defence mechanism against disappointment, or it can be the result of depression and anxiety disorders. Pessimists often justify their attitude by saying that they’ll either be vindicated or pleasantly surprised, however a pessimistic attitude may also limit potential positive outcomes. It should also be noted that pessimism is something very different to skepticism: the latter is a rational approach that seeks to remain impartial, while the former is an expectation of bad outcomes.

Perhaps the worst aspect of pessimism is that even if something good happens, you’ll probably feel pessimistic about it anyway.