In 2005, as if by magic, Web sites, TV talk and news shows, newspapers and magazines were filled with stories about how the Baby Boom Generation was going to be turning 60. In 2008, further illustrating the continuing association of the Boomers and the Beatles, the cute features were about the song “When I’m 64,” Paul’s jaunty little ditty that asked: “Will you still need me/Will you still feed me/When I’m 64?” And there’s not much risk in predicting that when the first Boomers reach full Social Security retirement age–now 66 for those born between 1943 and 1954–there will...