A doctor who was on call at my hospital the other night left me a voicemail the next morning as he was going off duty to tell me about the book he had been reading overnight. He had found my name and address on the inside front cover and some notes I had written on the blank pages in the back. It turns out it was one of the books I had given to a used book store in New York in 1970 to thin my collection before moving to Boston.