“Without forgetting, we would have no memory at all,” says McGill scientist Oliver Hardt. By that he means that if we remembered everything that happened to us with equal clarity, our brains would be crammed full of useless information. It would be nearly impossible to separate the wheat from the chaff—the important from the meaningless. Recent research is changing the view on forgetting, suggesting it is an active biological process that clears the brain of unimportant memories. This research may have implications for Alzheimer’s and other causes of memory loss.