 Samuel Delany's great surrealist SF classic, "Dhalgren," features the main character discovering a diary that appears to be written by a version of himself, with incidents that usually reflect, but sometimes contrast with the main narrative.The last section of the book is taken up entirely by journal entries, about which we must choose whether to take as completing the narrator's own story.Similarly, in Kiese Laymon's "Long Division", the main character discovers a book, also called "Long Division", featuring what appears to be himself, except as living twenty years earlier.