Why do we think we understand the world more than we actually do?

# Summary The illusion of explanatory depth (IOED) describes how people overestimate their understanding of everyday concepts until asked to explain them in detail. When forced to articulate how something works—like a toilet, lock, or car engine—people often discover significant gaps in their knowledge that weren't apparent before. This cognitive bias reveals the difference between surface familiarity with something and genuine, comprehensive understanding of how it actually functions.