In 1999, psychologists Daniel Simons and Christopher Chabris ran an experiment that's since become famous. They showed people a video of students passing basketballs and asked them to count the passes. Halfway through, a person in a full gorilla suit walks into the middle of the frame, thumps their chest, and walks off. About half the viewers never see the gorilla. Not because it's hidden. It's right there, in plain sight, for nine seconds. They miss it because their attention is locked onto...