"It was the best of times, it was the worst of times" begins one chapter of critically acclaimed Lee Siegel's new novel, Love and the Incredibly Old Man . "In the beginning" starts another. What else can a novelist do when hired as a ghostwriter by an elderly, irascible, conquistador-costumed man claiming to be the 540-year-old Juan Ponce de Le n? The fantastic life of that legendary explorer--inventor of rum, cigars, Coca-Cola, and popcorn--is the...