Can a bamboo hula be the foundation for a life well-lived? It was for Joan Anderson, the Australian immigrant to Los Angeles, who brought the rechristened hula hoop to America, where it became the prototypical craze of the crazed late 1950s. Even though the millions in profit went to the partner who seized the idea, converted it to plastic, and ran with it, Anderson, in her 90s, still seems a little stunned by what she and her husband wrought. Filmmakers Amy Hill and Chris Riess find the perfect jaunty tone in celebrating the ultimate icon of the baby boom generation.