Great writers know that the best humor isn’t found in jokes; the best humor is found in stories.
Genuinely great humor is about loss, refusal, and recovery. It’s not about two guys walking into a bar where there’s a twelve-inch pianist or a talking dog; genuinely great humor isn’t about limericks but about life. If you read Aristophanes, Pope, Behn, Thackerey, Austen, Jerome K. Jerome, Robert Benchley, Dorothy Parker, and Nora Ephron, you'll notice that only a few of what one might call their major pieces rely on the word "Nantucket."
Humor that remains humorous—and memorable--after fifteen minutes (or hundred years) is material that’s slightly dangerous and more than slightly smart.
All great humorists run towards what bothers them, what pains them, what disturbs them, what is, to them, unbearable—and then they deliberately trip over it. Some do a pratfall, some a stumble, some an apoplectic version of St. Vitus dance, some a soft-shoe, but none--and this is the important part--remain on their knees.