This story began, like so many in the history of science, with something we were not looking for. In 2020, during the COVID-19 pandemic, we were studying a practical question: How do people move around in an enclosed space when you ask them to keep apart from one another? Watching the footage time after time, we noticed something odd: Almost every participant walked in loops that turned in the same direction, always counterclockwise. Stranger still, none of them seemed to have noticed they were doing it.