“An indirect but certain proof of the fact that people feel unhappy, and consequently are so, is also abundantly afforded by the terrible envy that dwells in all. In the circumstances of life, on the occasion of every superiority or advantage, of whatever kind it be, this envy is roused and cannot contain its poison. Because people are unhappy they cannot bear the sight of one who is supposed to be happy.”

– Arthur Schopenhauer, On the Vanity and Suffering of Life