If Atul Gawande were funny--or Jerome Groopman were a working mother--they might sound something like Michelle Au, M.D., author of this hilarious and poignant memoir of a medical residency. Michelle Au started medical school armed only with a surfeit of idealism, a handful of old ER episodes for reference, and some vague notion about "helping people." This Won't Hurt a Bit is the story of how she grew up and became a real...