Watching RESCENE videos, they seem to know a lot about old pop culture

They even pick movies like Oldboy,
which came out long before they were born.
Liv even does Bae Sam-ryong's "dog leg dance,"
and when Liv sings the famous intro to Clon's song, "Bap bap dirara~,"
Jenna follows up with "Dirara dirirara~"
For them, stuff like that
must be the same as 70s movies or songs are to me.
How do they know all this? It's amazing...
Most 70s songs sound unfamiliar to me....