Blueprint of Ignorance by Daniel K. Wright

Do you know how a toilet works? You probably said "yes." Now, take a piece of paper and draw the mechanism inside the tank. Explain exactly how the flush happens. Most people fail this test. They draw impossible machines. This is the "Illusion of Explanatory Depth." We mistake our familiarity with objects for an understanding of how they function.

This book explores why we are all much dumber than we think we are. We outsource our knowledge to the world around us—to other people, to the internet, to the environment—yet we retain the feeling that the knowledge is in our own heads. Understanding this illusion is key to intellectual humility. It explains why political arguments are so polarized (people think they understand policies they can't explain) and how forcing someone to explain the "how" rather than the "why" softens extreme views.