We have all felt that inevitable late-afternoon crash, utterly convinced our willpower tank is completely empty. For decades, traditional psychology taught us that self-control was a finite resource—a biological battery slowly drained by every decision, stressor, and resisted temptation throughout the day. But what if that battery is entirely imaginary? Exhausted by Belief unravels the fascinating replication crisis surrounding the famous "Ego Depletion" theory. Through rigorous new studies and neurological mapping, scientists have discovered a startling truth: willpower is not a physiological limit, but a psychological framework heavily influenced by our own expectations. This book dissects how our beliefs about mental fatigue actively manifest physical exhaustion. You will learn how the brain conservatively safeguards energy reserves it does not actually need to protect, and how shifting your perspective on mental stamina instantly unlocks hidden cognitive reserves you never knew you had. By dismantling the idea of a limited willpower tank, you can fundamentally rewrite your approach to focus, diet, and daily productivity. Discover how to reprogram your mental limits and sustain high performance without falling victim to the illusion of the crash.