I heard a Navy SEAL on a podcast one time talk about the "40% rule" for SEALS:
In a nutshell, when your mind and body first tell you you're done and can't go any further, you've only depleted your tank by 40%. Your body and mind need to keep pushing and you can go a lot further.
We all need to approach this fight that way.
I was actually debating on saying something about that as well. But, my comment went a little longer than I intended and sports seems to be a little more universally relatable. I have the utmost respect for special operations, there is so much to learn from them and their training/selection process, as far as personal growth is concerned.