Quite an interesting question, and at that, one difficult to answer. I recently read Fight Club by Chuck Palahniuk, and while I do not have a multiple personality disorder (I think...), I related a lot to the main character, as well as Tyler Durden. To be honest I wouldn't ever say one book could ever come close to describing me, more the collection of books I have related to on some level. Tweak, by Nic Sheff could describe me, except a large portion of that book focuses on methamphetimine, and that particular nuance doesn't really describe me in the slightest. If I had to answer the question, as it is word for word, I would have to say that Ender's Shadow, by Orson Scott Card, come's the closest. The main character's thought process, and his actions are so very similar to mine that it was scary. Bean's mantra, "Know think choose do", made incredible sense to me, given any context.