Billions of dollars can buy a lot. Lavish houses, luxury cars, elegant yachts, expensive clothes, dining extravaganzas in the best restaurants in town. Travel to exotic destinations. Billions can bring power and fame — and opportunities to contribute to the causes of humanity. But there are three things billions cannot buy. Peace of Mind Sanity Friendship The Bottom line: Billions can buy many amenities and trophies, the necessary conditions to getting a good life, but they cannot buy peace of mind, sanity, and friendship, the sufficient conditions for maintaining a good life.