In the bottom drawer of my desk is an old cassette tape (now you know how old it is!), with these words scribbled on its label, “Don’t Worry, Be Happy.” Turns out it’s a 1988 a cappella recording of composer-singer Bobby McFerrin, singing and whistling the jingle: “Here’s a little song I wrote, you might want to sing it note for note—Don’t worry, be happy. . . . In every life we have some trouble, but when you worry you make it double—Don’t worry, be happy. . . .