A few years ago, I walked through a very old cemetery a few miles from my house. I never realized just how old it was... many graves dating back to the early 1800's. A lot of the headstones were so worn they were difficult or impossible to read.
What struck me was the large number of people who lived 90 years or more. Often, there were two large stones of parents who lived into their late 80's or 90's flanked on either side by the smaller stones of children who died in infancy or early childhood. It seemed that if you made it past childhood illnesses that are rare today because of vaccinations, and didn't get killed in a war or accident, that a hell of a lot of folks who lived tough hard lives still lived to ripe old ages. I had always thought the life expectancy was typically much shorter back then, but it was the law of averages that made it seem so.