Who is Joan Didion anyway? In The Last Love Song: A Biography of Joan Didion, Tracy Daugherty decided to find the writer in her most public work. “Does the life reveal the art, the art the life?” he asks in the prologue (xxiii). If you find fault with The Last Love Song it will be in this decision — not in Daugherty’s entertaining style, which often reads like the New Journalism that Didion helped to establish; nor in his …