The Housekeeper and The Professor, by Yoko Ogawa, is a short and tender book. Two main topics are memory, which I know something about, and math, which I know nothing about but which is utterly fascinating (see also The 351 Books of Irma Arcuri, for a guy with a serious math thing). In Japan, a housekeeper and her son are drawn into the world of a mathematically brilliant but severely memory-impaired professor, whose anterograde memory — his ability to acquire new memories) is limited to 90 minutes. He sticks post-it notes on his raggled old suit the way the main character in the movie Memento tattooed important facts about his life onto his body (without the sinister consequences).  Each character gives something meaningful and intangible to the other in this story, and there’s a beauty here that goes beyond the beauty of mathematics. — Lisa