The renowned naturalist, Loren Eisely, observed that we humans have given up the "certainty of the animal that what it senses is exactly there in the shape the eye beholds." The big question is, what did we get in return?This book provides a convincing answer to this question, arguing that, instead of recording reality, your brain uses your experience to create a story, a narrative, about how what happened to you in the past led to what is happening to you now. This narrative is your private reality. The book continues by showing how replacing recorded reality with private narrative enabled humans to anticipate the fundamentally unknowable immediate and remote future and expose potential threats. It then shows how private narrative enabled complex thought and communication with others. Drawing upon a wide range of research, the book provides a stimulating new way of viewing human experience, thinking, communicating, and action.