Culture is Fantasy
Your arguments of culture are all based on fantasy...a social created reality. That's right your culture is as malleable as your sense of reality. You see we humans are symbol users (Burke), we imbue objects with meaning. If we wanted to we could totally change the letter C to some kind of symbol like >~ give it the phonetics of C and there ya go, it does the same thing just looks different.
Let's say a giant reset button was hit (the way things are going in this world you'd think the reset button is going to be hit soon) and the only artifacts future humankind could find were pictures of professional wrestlers. One person in the tribe is convinced that this was the cultural heritage of the Fallen World. She/he happens be a very convincing person and goes out to convince people their cultural heritage is dressing like a wrestler (I'm thinking Hulk Hogan), they must have ritual fake fights to settle disputes, and must all be bulked up dudes and busty women. Enough people see the evidence and believe the speaker, that soon chains out into their world and before you know it the Culture of Hogan is born. Everyone is eating their vitamins, saying their prayers and growing really gay mustaches (well the dudes).
Come to think of it that would make a great sci-fi story. I'd call it The Poor Future or The Once and Future King of the Ring and tell it as the society learns its heritage and chains it out till men are shaving the tops of their head, tanning all day and women are... well what do the women in wrestling do, besides have big boobs?