In any one particular year as we age, a few memory gadgets get worse, a few get better, and a few don’t change at all. 2. Most everything declines after age thirty. Working memory, for example, peaks at age twenty-five for most people, stays steady until thirty-five, then begins its long slow journey into the night. Episodic memory peaks five years earlier than working memory, then takes the same slow slog as its working cousin.