Richelle E. Goodrich said this quote

Life is too hard to maintain a constantly serious outlook. You have to laugh at yourself and the world now and then―see humor in undesirable circumstances, even harsh situations―or you will either rot from the inside or go stark-raving mad. Humor is power against the worst oppression. It lightens heavy burdens; it allows one to smile while in agony; it eases excruciating pains. In short, humor makes the intolerable tolerable.