Most of us have no idea what's really going on inside our heads. Yet brain scientists have uncovered details every business leader, parent, and teacher should know - like that physical activity boosts your brain power. How do we learn? What exactly do sleep and stress do to our brains? Why is multi-tasking a myth? Why is it so easy to forget - and so important to repeat new information? Is it true that men and women have different brains? In Brain Rules, John Medina, a molecular biologist, shares his lifelong interest in how the brain sciences might influence the way we teach our children and the way we work. In each chapter, he describes a brain rule - what scientists know for sure about how our brains work - and then offers transformative ideas for our daily lives.