There’s something that has my curiosity when I go for a swim at my neighborhood beach. It’s a salt water beach in Rhode Island along Narragansett Bay’s Sakonnet Passage/River. We’re allowed to drive right onto the beach and park. The beach consists of mostly gravely sand, and a lot of broken shells along the wrack line. When I walk barefoot across that gravel and shells walking to the water to begin my swim…it’s almost like walking on broken glass. It genuinely hurts my bare feet to walk across it. But then, after an hour or more of swimming, when I exit the water to walk back to my car, it’s almost unnoticeable. The only thing I can figure is that the skin on the soles of my feet becomes softened from being in the water, and more pliable. But you’d think just the opposite would happen, and the dry, toughened soles would form a more resistant barrier.