The little H2Os that I was so earnestly hoping would not splash back at me were probably veterans of thousands, hundreds of thousands, maybe even millions of round trip excursions into and out of dinosaur bladders. Physicists on the other hand know all the formulas. Give them one data point and they can extrapolate the rest of the graph. It was many months later that the full implication of my lab-mates' responses became clear to me. No one wanted to confront the fact that every glass of water that one drank contained molecules of H2O that have been through countless millions of kidneys and bladders.
Nature is the ultimate recycler.
Even the big bang was made from previously used parts. Still, all in all, it might be better to hold within ones collected consciousness just a small remembrance of ones place in the massive scheme of things. We are renters in every sense of the word.