Not to cast any shade on the old favorites — A Christmas Carol, “A Visit from St. Nicholas,” Amahl and the Night Visitors, etc.; they are all famous for a reason. But if you have The Stories of John Cheever — and if you don’t, why not? — look up “Christmas Is a Sad Season for the Poor.” It is very of its time, a classic old-fashioned New Yorker story, set in a city of the same time, when elevator men in East Side apartment buildings were white ethnics who lived in rooming houses. Cheever writes with a light touch, but tells a lot about self-pity, generosity, and why we spend so much time on the former, and more than you might think on the latter.