I got an email from a guy who said that he was really depressed and was about to hurt himself when a friend called and asked him to go dancing. He said no, he didn’t want to go out. And then after he hung up the phone, he remembered that line: “Exercise gives you endorphins. Endorphins make you happy.” So he called the friend back, went dancing, had a great time, decided not to kill himself and wrote me a letter saying, “That line saved my life.” I was weeping [reading that]. What an offhand line to end up being so meaningful to someone. That blew my mind.  (x)