This book is one of my favorites, possibly the best book every written. It's amazing how many puzzles and mysteries come out of this short novel--people still find new links (and bobolinks!) to different ideas in it. One thing to ponder--who is real, who is a creation of another character in the novel? Is John Shade the creator of Kinbote, is Kinbote the creator of Shade? Or are both real? Does Gradus really exist, or is he another Zemblan character? Did Professor Botkin (think Pnin) create Kinbote?
My favorite link is the daughter's name, Hazel Shade, one very much like Dolores Haze (Lolita's real name).
READ HOUSE OF LEAVES, it asks the very same questions about reality and narration, and is an awesome horror story.