Why believe in “optimism” rather than “pessimism”?
What if optimism is naively leading you to absurd conclusions? Or perhaps there’s a better way of doing something and if only you could stop what you are doing now and become pessimistic about it would you realize this. Realize what exactly? An instinctual urge to view negative possibilities as more realistic than positive ones? Wait, don't confuse “pessimism” with “resignationism”, like Schopenhauer did, and don't confuse “laughing” with “optimism”.
There are pessimistic laughers too, my favorite kind.
Suggested reading:Nietzsche. The Birth of Tragedy, Attempt at a Self-Criticism. §6 (click here.)