> like every work of literature that characters reference is from the 20th c A lot of literature today refers to bronze age religious texts(2700 years ago), Sh

> like every work of literature that characters reference is from the 20th c A lot of literature today refers to bronze age religious texts(2700 years ago), Shakespeare(400 years ago), the Ramayana(2600-3kya), Romance of the Three Kingdoms(600ya), and so on. There are threads of Porto-Indoeuropean mythology preserved in the Vedas, Roman Mythology, and the Scandinavian Sagas. I don't know much about Australian Aboriginal mythology, but there's strong evidence that their stories contain accurate details of extinct species and geographic features from thousands of years ago. So it seems entirely possible that enough cultural material from the mid 20th century will survive until the 2500s for people at that time to have a good understanding of the 1950s in at least some places.