I can imagine how the transitions they experienced through the 1950s, 1960s, and 1970s may have seemed to them much like how my world evolved in the 1980s, 1990s, and 2000s. While I can surely find some milestone events in my personal life, I do not see stark boundaries I would consider truly different ages/eras for society as a whole. I remember how every recent transition took years and perhaps never completed.
I wonder if certain cultural artifacts and stories in history and pop culture give us a more consistent sense of past eras/ages prior to our own experiences. Things like railroads, electrification, automobiles, film, the great depression, airplanes, films with sound, color film, TV, antibiotics... they all were smeared over many years but we can easily ignore that when talking about the past.