If you like maths at a hobby level, this is a great book. Bite-sized explanations of many theorems, conjectures, formulas, rules, fallacies and paradoxes. Have you heard of the hairy-ball theorem? The blue-eyed suicides? Cantor dust? They're all here! (Hilbert's hotel, oddly enough, is not.) The book would have benefited from some more illustrations and omission of the chapter on mathematical physics (which is hardly about maths at all).