Why did we win the one hundred man battle when we could not even stand straight in the end? The remaining 22 fighters could have easily fell us, yet they've lost their motivation to fight because their goal could not be fulfilled anymore, so they turned away and left while we refused to lay down and die, leaving us victorious. Why did Yifang lose despite being a better swordsman than we are? Because she doubted what she was doing, and that is the last thing you want to do in a fight. She would have been dead by now if Lanhai didn't feel the same, which led to her and her husband's defeat. Finally, why did Xuxian fail the test? There was a multitude of reasons, but ultimately, wasn't it because for a second he wanted to be anywhere but here? His lack of determination and confidence paved the road to fear, which in turn led to the loss of control.
Do not underestimate the role of passion and a proper motivation in a fight. Our iron will and stubbornness carried us through a lot of situations where a weaker person would just give up. Maybe overzealousness is just the right mood you want to face an impossible challenge with.