Happiness and suffering, however extreme, are mental events. The mind depends upon the body, and the body upon the world, but everything good or bad that happens in your life must appear in consciousness to matter. This fact offers ample opportunity to make the best of bad situations—changing your perception of the world is often as good as changing the world—but it also allows a person to be miserable even when all the material and social conditions for happiness have been met. During the normal course of events, your mind will determine the quality of your life.

p. 204 - Waking Up (2014)