I think that this doesn't address the important element that things like special training courses aren't wholly about "succeeding" or "failing," especially when

I think that this doesn't address the important element that things like special training courses aren't wholly about "succeeding" or "failing," especially when we're making statements like it being all about the mind. The Army, in its special forces personnel, is looking for a very specific group of people, and the challenges are designed to weed out those people from everyone else who is going through the course. Any good selective interview or course like this should be designed that the company/division is testing who the candidates are that meet their desired overall profile--in which case, not passing the test or course isn't a failure or demonstrative of a lack of ability on the candidate's part, but rather a lack of fit for that specific position or unit.