"Fretting makes us important. Say you're an adult male and you're skipping down the street whistling "Last Train to Clarksville." People will call you a fool. But lean over to the person next to you on a subway and say, "How can you smile when innocents are dying in Tibet?" You'll acquire a reputation for great seriousness and also more room to sit down. ...Being gloomy is easier than being cheerful. Anybody can say "I've got cancer" and get a rise out of a crowd. But how many of us can do five minutes of good stand-up comedy?"