A bumper crop of moans and groans from the man who discovered that arms were getting shorter, print getting smaller and martinis getting weaker in middle age-snaps back at daily doings, pet peeves and the unpleasantness of the world around him. Name the subject -- diet, TV, do-it-yourself, weekending, Christmas, jokes, memory, men -- and women, picnics, the office, operations and hospitals, skiing, batching it in the summer, amateur photography, collecting, living in the country -- or the city or just living, and there it is in a wonderfully warped mirror. This gathers in some oldies -- parodies of early years on Hemingway, Faulkner, the Norrises, Dreiser, Masefield, and tosses in an instructive series on how a dog can train a man. Maybe it doesn't bowl over Benchley but it curves some neat ones to home base. An entry for the wry grin department.