I think you're half right. Willpower is bolstered by a belief that it is infinite, but in reality, it is finite. To go even further than that, those who believ

I think you're half right. Willpower is bolstered by a belief that it is infinite, but in reality, it is finite. To go even further than that, those who believe they don't have a willpower limit are more likely to continue challenging it and developing it - paradoxically increasing it. Those who believe they have a limit may exercise it less. The same effect can be seen in sports psychology. Those who believe themselves indomitable can squeeze out extra force/endurance in physical trails, whereas those who believe themselves fragile perform at a weaker state.