What kind of man creates a boy who never grows up? More than 100 years after "Peter Pan" first appeared on the London stage, author J. M. Barrie remains one of the most complex and enigmatic figures in modern literature. A few facts, of course, are widely known: "Peter Pan" made Barrie the richest author of his time, and he bequeathed the royalties to the Great Ormond Street Hospital for Sick Children. He was married, but later divorced, and he was...