Stoicism

"We suffer more often in imagination than in reality."

"You have power over your mind — not outside events. Realize this, and you will find strength."

"The best revenge is not to be like your enemy."

"Waste no more time arguing what a good man should be. Be one."

"It's not what happens to you, but how you react to it that matters."

"No one can hurt you without your permission."