We tend to lament our propensity to forget with age. But the truth is, the only way to remember the vast amount of data we do—from one's address to a best friend's favorite color—is, paradoxically, to forget.

Scientists have begun to understand the importance of forgetting in remembering, says Neil Macrae, Ph.D., an experimental psychologist at the University of Bristol in England. Every time we recall a fact, like where we parked the car, we also unconsciously curb connected but extraneous facts, like where we parked last week. This automatic—and crucial—phenomenon is known as temporary forgetting. True, the memory-boosting mechanism can backfire. Macrae has found that when cramming for a test, for example, we repress any related facts that we neglected to study, making it harder to recall them on exam day. Still, the ability to remember life's details renders its downsides trivial. Without temporary forgetting, one would be unable to furnish one's telephone number or the name of one's favorite Pink Floyd album.