This is an exceedingly strange novel. The main character (and author) is Charles Yu; he lives in a small time machine with his non-existent dog and a depressed AI. After accidentally encountering and shooting a future version of himself, he takes a book from his dying future self named How to Live Safely in a Science Fictional Universe (by Charles Yu) and then tries to change his future by rewriting the book. There is a fair amount of philosophy and introspection throughout, with Yu trying to come to grips with his relationship with his father, the way you see someone as a child and then later as an adult. Much of the writing is stilted and complicated, often taking a second pass to properly parse. "conjectures, currently unproven but believes to be true ... That chronodiegetics is a theory of the past tense, a theory of regret. That it is fundamentally a theory of limitations." Coupled with an unsatisfying conclusion, I was quite disappointed in a book that has generally been well-reviewed and I expected to really like.
There is just enough space here for one person to live indefinitely, or at least that's what the operation manual says.