For forty years, RM Vaughan has been fighting, and failing, to get his forty winks each night. He's not alone, not by any stretch. More and more studies highlight the health risks of undersleeping, yet we have never been asked to do more, and for longer. And we can't stop thinking that a lack of sleep is heroic: snoozing is a kind of laziness, after all. But why, when we know more about the value of sleep, are we obsessed with twenty--four--hour workdays...