I'm reading the book right now for the first time. When Rincewind and Twoflower are falling after Twoflower's dragon disappears, Rincewind tries to imagine a dragon to rescue them. They end up in another universe, in an airplane and someone else's body. Rincewind was in the body of a doctor that was listed as age 33. Since this is a parallel universe, I wonder if that also means that Rincewind is 33.