Fleming shows that those frustrating moments of knowledge just beyond our grasp aren't some kind of design flaw in our minds. Surprisingly, they are actually examples of our brain's greatest power. Scientists and philosophers call it metacognition, but you might just call it the ability to think about our own minds. Metacognition enables us to answer questions as straightforward as what skills we need to practice or what facts we need to study to do better on a test. And it is the reason we can wonder about issues as big as what we should do with our lives. At least as far back as Socrates, philosophers have encouraged us to know ourselves. Fleming reveals both the science of how we do it and why it matters--and how we can do it better.