When I was a little kid growing up on the South Plains of Texas my grandfather would take me with him in his truck to the markets in San Antonio to buy watermelons in late spring when they first arrived from Mexico and the Rio Grande Valley. On the way back we would stop at grocery stores to sell as many as we could and then we'd park under a tree by the side of the road and sell them to anyone who stopped.
One of the highlights of the return trips for me was getting to ride in the bed of the truck and, once in awhile, when I thought he wasn't looking, throw a watermelon over the tailgate just to see it explode on the pavement.
Ten or twelve years later, when I started riding motorcycles, I remembered that image very, very well and never, ever rode without a helmet.