Be mindful of the company you keep. Don’t let negative people cloud your vision.
The Happiness Code: Ten keys to being the best you can beOnce you learn to be happy, you won’t tolerate being around people who make you feel anything less.
The Hope Handbook for Survivors: The Seach for Personal GrowthOther people's heads are too wretched a place for true happiness to have its seat.
Parerga and Paralipomena: Short Philosophical Essays, Vol 1: Parerga