Except ego depletion hasn't stood up as well as a scientific concept after more rigorous replications. Indeed, there's research that shows that the way you think of your own willpower affects its depletion. If you believe that you're "energized" by doing hard things, you tend not to get depleted after exerting willpower. If there really were a physical store of energy, then your beliefs about it shouldn't affect it. Yet they do.