In his most extraordinary book, "one of the greatest clinical writers of the 20th century" (New York Times) recounts the case histories of patients lost in the bizarre, apparently inescapable world of neurological disorders. It tells the stories of individuals afflicted with fantastic perceptual and intellectual aberrations: patients who have lost their memories and with them the greater part of their pasts; who are no longer able to recognise people and common objects; who have been dismissed as retarded yet are gifted with uncanny artistic or mathematical talents. If inconceivably strange, these brilliant tales remain, in Dr Sacks splendid and sympathetic retelling, deeply human.