This was no coincidence. The best short stories and the most successful jokes have a lot in common. Each form relies on suggestion and economy. Characters have to be drawn in a few deft strokes. There's generally a setup, a reveal, a reversal, and a release. The structure is delicate. If one element fails, the edifice crumbles. In a novel you might get away with a loose line or two, a saggy paragraph, even a limp chapter. But in the joke and in the short story, the beginning and end are precisely anchored tent poles, and what lies between must pull so taut it twangs.