Story Theory is a practical model of how the brain works as it executes its mission to help us survive and thrive, providing simple and powerful tools to achieve peace of mind, happiness and any other desired emotional state of well-being. At Story Theory's foundation is the intersection of evolutionary psychology, the dual-system brain hypothesis as postulated by Bargh & Chartrand and others, and recent neuroscience known as simulation theory. It describes the system of thinking, feeling and ultimately behavior that the brain evolved in the face of energy scarcity hundreds of thousands of years ago and how this system is a main source of anxiety and unhappiness we feel today in our modern world. It then illuminates the solutions to rejecting the limitations of this system and taking control of our feelings and behavior, resulting in a hugely improved life, both in terms of happiness and success.