That’s not a good book, that’s the best book. When you want to read slowly because you enjoy the book so much you don’t want to end, but you also want to read fast so you can find out what happens!
The best thing is that, with a book, you can keep your friends close. Re-reading your favourite books is like revisiting that lost friend. There’s nothing like reading a new book and discovering how good it is, but reading an old friend is almost as good. Especially when you have an aging memory. Then all your best friends are new again. Probably one of the few benefits of such a memory.