As a kid, I spent a lot of time at the beach with my grandparents in Ocean City, New Jersey. I have fond memories, many of them of my grandfather humming something while working or cooking. Once I asked him what song he was singing, and he answered “the Air Corps song.”
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.