I'm always somewhat surprised to discover how many of the writers and thinkers I've admired over the years grew up reading Eugene O'Neill with a passion equal to my own. For years, I thought of O'Neill, who spoke so deeply to my adolescent self, as a kind of private pleasure. So I experienced something of a jolt when, in 2006, Joan Didion told me, during an interview, that as a girl she'd read all O'Neill's works in …