THE WORDS “retirement community” summon up images of easy chairs, overcooked food and endless daytime TV. Latitude Margaritaville, a community being built near Hilton Head Island in South Carolina, quickly disabuses these. “There was a toga party this past weekend,” says Lynette, a resident. “There was a live band, and it was a riot.” Barbie, another of the community’s “ambassadors” (residents employed by the developers to help sell it to potential newcomers), compares living there to “starting college all over again”. There are, she says, “drinks on the driveway, cocktails on the concrete”. If Margaritaville’s residents are representative of their...