“To be someone's best friend requires a minimum investment of time. More than that, though, it takes emotional energy. Caring about someone deeply is exhausting.”

“Nothing frustrates me more than someone who reads something of mine or anyone else's and says, angrily, 'I don't buy it.' Why are they angry? Good writing does not succeed or fail on the strength of its ability to persuade. It succeeds or fails on the strength of its ability to engage you, to make you think, to give you a glimpse into someone else's head—even if in the end you conclude that someone else's head is not a place you'd really like to be.”

“What does it say about a society that it devotes more care and patience to the selection of those who handle its money than of those who handle its children?”

“The principle elements of a puzzle all require the application of energy and persistence, which are the virtues of youth. Mysteries demand experience and insight.”

“A study at the University of Utah found that if you ask someone why he is friendly with someone else, he’ll say it is because he and his friend share similar attitudes. But if you actually quiz the two of them on their attitudes, you’ll find out that what they actually share is similar activities. We’re friends with the people we do things with, as much as we are with the people we resemble. We don’t seek out friends, in other words. We associate with the people who occupy the same small, physical spaces that we do.”

“Mimicry, they argue, is also one of the means by which we infect each other with our emotions. In other words, if I smile and you see me and smile in response—even a microsmile that takes no more than several milliseconds—it’s not just you imitating or empathizing with me. It may also be a way that I can pass on my happiness to you.”

“A critic looking at these tightly focused, targeted interventions might dismiss them as Band-Aid solutions. But that phrase should not be considered a term of disparagement. The Band-Aid is an inexpensive, convenient, and remarkably versatile solution to an astonishing array of problems. In their history, Band-Aids have probably allowed millions of people to keep working or playing tennis or cooking or walking when they would otherwise have had to stop. The Band-Aid solution is actually the best kind of solution because it involves solving a problem with the minimum amount of effort and time and cost.”