S. J. Perelman, it turns out, left behind four chapters of an autobiography when he died in 1979. He planned to call it "The Hindsight Saga," a perelmaniacal spin off "The Forsythe Saga." These bits of memoir, published for the first time in "The Last Laugh," are the tailpiece to a collection of 17 of Perelman's comic sketches for The New Yorker. Even in its fragmentary state, "The Hindsight Saga" strikes me as the best thing Perelman ever wrote….

Perelman wrote steadily until the day he died at the age of 75, and from the beginning of his career to the end he was capable of being the funniest writer in America—over the quarter-horse distance of 1,500 words. Reading his little sketches, I grew used to hearing myself laugh out loud during the opening romp. Then, before I knew it, I would find my fingers rustling through the pages ahead to...