Like most boys of the 1950s I collected stamps. For a brief while I joined, at the age of twelve, a stamp club. Even at that early age I could recognise that some of the adult members were rather odd people. They were driven collectors, obsessed with the minutiae of differences and errors in stamps. Simon Garfield is one such collector and his new book succeeds, against all the odds, in making his mania interesting and, to a degree, comprehensible.