Toughness & The fire of the mind.
I really want to share this video. Watch it before reading my comment, please.
Believing that you will fail because you are tired, hurt, weak or inferior is almost a guarantee that it will happen. In fact believing that you are tired, hurt, etcetera may actually create that condition where it did not exist. Your subconscious controls your actions to prevent you from pushing yourself too hard, or as a tool to heal you by faith, which is a good thing. It can also be used to destroy you if you hand it over to your doubts, worries and fears. To take some liberty with a quote from George Washington (pun intended):
Your subconscious, like fire, is a dangerous servant and a fearful master.
Being tough is really about not believing that you are hurting or suffering even if you think you should be. Since I am already abusing quotes today, consider the following:
A Native American grandfather was talking to his grandson about how he felt. He said, “I feel as if I have two wolves fighting in my heart. One wolf is the vengeful, angry, violent one. The other wolf is the loving, compassionate one.” The grandson asked him, “Which wolf will win the fight in your heart?” The grandfather answered: “The one I feed.”