He had to keep reminding himself that he had five years to go at Hogwarts, and how it would feel to ask the Dursleys for money for spellbooks, to stop himself from buying a handsome set of solid gold Gobstones (a wizarding game rather like marbles, in which the stones squirt a nasty smelling liquid into the other player’s face when they lose a point). He was sorely tempted, too, by the perfect, moving model of the galaxy in a large glass ball, which would have meant he never had to take another Astronomy lesson.