"Once, in his first term, Cartwright had been bold enough to ask him why he was clever, what exercises he did to keep his brain fit. Healey had laughed. "It's memory, Cartwright, old dear. Memory, the mother of the Muses... at least that's what thingummy said." "Who?" "You know, what's his name, Greek poet chap. Wrote the Theogony... what he called? Begins with an 'H'." "Homer?" "No, dear. Not Homer, the other one. No, it's gone. Anyway. Memory, that's the key."