People only use about 10% of their brain. It’s a fact we’ve all heard—except it isn’t a fact at all. It’s a myth. While activity in some brain regions fluctuates depending on what you’re doing, you use pretty much all of your brain , all of the time. And yet according to surveys of teachers conducted around the world, about half said they believed this 10% myth to be true. How do such falsehoods make their way into our (fully utilized) brains? One way, it turns out, is through repeated