“Some people might think that the smartest way to guarantee their own well-being is to isolate themselves from others and to work hard at their own happiness, without consideration for what other people are experiencing. They probably assume that if everybody did that, we’d all be happy. But the result would be exactly the opposite: instead of being happy, they would be torn between hope and fear, make their own lives miserable, and ruin the lives of the people around them too.”