May be some genetics at work, too, I suppose. Mr. Mew's family is full of folks with thin and/or weak tooth enamel. Their teeth need all the help they can get. Maybe this gentleman you mentioned has really strong teeth. Wonder if he gargles and/or flosses?
I don't think he does, but he does come from really tough "peasant" stock, and still lives in a very active way...built his own house, 4 acre pond, etc.
We are all different, and have different strengths and resources. Perhaps those who are closer to the old-world "survivors" share a lot of their chartacteristics. It may be a high price to pay, though...but still, I think we would all be better off without some of our modern conviences and luxuries.