Oh, don't worry it precisely; there are different threads he follows; there are the ones about Rincewind (the first two and Eric, in particular), the ones about the other wizards at Unseen University, the ones about the Night Watch, the ones about the witches from Lancre, the ones about Death, and his granddaughter, and the stand alone ones, like "Pyramids", as well as the "young adult" ones in that world, "The Wee Free Men", "The Amazing Maurice and His Educated Rodents", etc.