Haha! Listen, the "you can do it if you believe in yourself" stuff always sounds bogus. But there was some stuff around ten years ago about this. Here's an example: https://www.pnas.org/doi/full/10.1073/pnas.1313475110#F1

Also when I last checked, "willpower as a finite resource isn't a thing" was simply the scientific consensus

But I agree that doesn't necessarily translate to "willpower is infinite"