On the flip side, can you imagine if Superman didn't fly every chance he got? Or if Daredevil didn't bother to canvas his surroundings before fighting an enemy? Or if Batman didn't test all the capabilities of all his gadgets before going out at night?
Steve Rogers doesn't run every morning because he needs to get in or stay in shape. He runs every morning to keep his mind sharp, his discipline strong, his habit unshakable. The bond between his mind and body are so strong that he becomes a force to be reckoned with.
And at 80 years old, when all his friends and loved ones are dead or dying, the discipline that he has cultivated is the only thing he knows he can count on.
What do you have in your life that you know with unshakable certainty that you can count on in a crisis?