It has been my experience that the power of belief allows me to dare. The power of belief allows me to be surprised at what I am capable of accomplishing. When you are at the absolute bottom of your perceived physical strength or endurance, a bit of positive thinking and belief in oneself can bring about a positive outcome.
Someone once said, "why does the bumblebee fly?" "Because he believes he can, and no one told him he couldn't."
"You were not there for the beginning. You will not be there for the end. Your knowledge of what is going on can only be superficial and relative" William S. Burroughs