That’s ten times more than many people think, according to Dr. Aaron Carroll, coauthor of Don’t Swallow Your Gum: Myths, Half-Truths, and Outright Lies About Your Body and Health. The false notion that most of our gray matter sits idle probably first cropped up in the early 20th century. “Snake-oil salesmen needed to convince people that they could be smarter,” says Carroll. “The oil is gone, but the myth is still around.” In fact, your brain resembles a running car. All of it works all of the time, but parts “rev up” depending on what you do. That means you keep losing your keys for other reasons. “If you don’t think you’re living up to your full potential,” Carroll says, “don’t blame it on the physical properties of your brain.”
