My mother (born 1926) always told me "people used to die young because they didn't have medicines" By the time 1958 rolled around I figured that was an exaggeration, because of all the "old" people I met with my Great Aunts.
Fast forward 20 years, when I began collecting the information for my genealogy, and I learned it was not true in our family. My biggest shock was finding my 5th great grandmother living in the 1850 census at the age of 100. Generations after her had children who lived to 85, 91, 80. The same was true on a couple of other lines.