Forgetting names, faces, or events is a universal human experience; even those who see their minds sharp struggle with memory loss from time to time. Most consider these mental mistakes to be annoyed, and they're seen as a potentially worrisome sign of cognitive decline. But neurologist Scott Small, who studies and treats Alzheimer's disease at Columbia University, thinks this view of forgetting is all wrong. In fact, some amount of forgetfulness is critical for our minds and relationships to function at their best.

We're developing drugs to protect against memory loss. But many psychologists have joked that what they want is a forgetfulness drug. Too much memory poses a challenge in any long-term relationship. Anger, hatred—they all come from not being able to let go of emotional memories. People who repeatedly think of anger or fear suffer, often in loneliness.

Living in a noisy, ever-changing world, forgetting details is actually a perfect adaptation. Creativity isn't making something out of nothing. It's making connections between already-known elements—ideas, words, visuals, or expressions—to create something new. But to make new connections, the existing connections in your mind have to be loose. If the connections between those elements are too tightly bound in our memory, there's no room for creativity.

What can we do to help our brains forget what we need to forget? One of the best ways to make sure that you don't have a brain that's burning too. hot with bad memories is to stay socially engaged. Another thing to do is to sleep, and sleep well. Many experts have concluded that we sleep in order to forget, so it makes sense that sleep has been shown to improve creativity. If you're short of sleep, your brain is on fire with too many memories. The brain is like a lawn of grass—you need to keep it trimmed to make way for new memories, new connections, and new growth.