"Learn like you are going to live forever. Live like you are going to die tomorrow." — Max Cavalera, Soulfly.
"Pessimism is just a word invented by optimists to discredit those who see the world as it really is." — Lewton, Discworld Noir
More of a maxim really: "It is unfortunate, but necessarily true, that in general the people with the most time to edit Wikipedia are those that are the least qualified to do so."