My seven-year-old granddaughter got to stay up late. It was New Year’s Eve, after all. Promptly at midnight, the lighted ball started to fall toward Times Square as thousands celebrated. She watched for a while with a child’s wondering eye. And then, as children often do, went to the heart of the matter: “Grandpa,” she asked, “What are they so happy about”? What indeed? How could I explain it to her? This great collection of seemingly gleeful people was celebrating a “