Sometimes, we get just 1 chance to do something right that is significant. But, being perfectly ready for that 1 chance does not take place at the moment of the big moment - but long before. In many cases the seeds of victory or defeat are planted years before.
A boxer goes into the ring having trained well, or not so well. He has been training for 1 year, or perhaps 10 years. Maybe even long before he began 'training' his life prepared him well to potentially become a great fighter?
Once in the ring there is no place to hide or feign greatness. He must fight and his mistakes are seen by all and painfully felt by himself.
If he wins he was ready and able...at least for that opponent. The losing fighter is made to taste the reality that he was not ready or able (at that point, mere willing is not sufficient for winning) - not for that opponent. Maybe he was not yet good enough. Maybe, he never will be good enough no matter how hard he tries (some lack aptitude for some things); or, maybe he could become better than his opponent someday.
The winning fighter's confidence and sense of worth are increased by that win, as they should be. But, what if he had just never fought very good oponents? He has beaten everybody in his village, but then loses to the first 10 fighters he fights in Philadelphia. Then, his sense of worth - insofar as it came from being a great fighter - was, perhaps, higher than it should have been.
A pretty good fighter may have never lost, whereas a much better fighter will likely have lost a lot...against better competition. He became better because of an aptitude for winning and, as importantly, an aptitude for handling defeat. Some would-be great fighters lose a fight and stop fighting...and, then they are never to become great fighters...since, they are no longer fighters! What makes a man continue to fight? Can we at least say it is a belief that he can eventually win?