Air Force Brig. Gen. Chuck Yeager has had an epic career. During World War II, he flew 64 missions and decimated 13 enemy planes. Though he was shot down during a mission in France, he evaded capture using the French Underground. When he returned home after the war, he was among several pilots to test the experimental Bell X-1 rocket plane, and became the first human to break the sound barrier in October of 1947.
Benjamin Franklin nailed it when he said, "Fatigue is the best pillow." True story, Benny. There's nothing like pushing your body so far past exhaustion that you'd willingly, even longingly, take a nap on a concrete slab.