I imagine that for much of our history, humans were unaware of how their lives compared to their ancestors, and just assumed that they way they lived was how humans had always lived. I suspect that they’re lack of awareness was due to some combination of religious beliefs about the origins of life and mankind, a lack of interest in learning about history, a lack of historical evidence indicating how ancestors lived, and a slower rate of advancement that was not apparent in one’s lifetime. When did humans start to show an awareness of the fact that they were more advanced than ancestors? For example, did ancient Greeks show any awareness of how Stone Age ancestors lived?
You might find this answer from u/ARealFool on the subject of historical consciousness interesting:
I actually bought that book but haven't fully read it yet! I get the impression it might go a bit over my head from what I've read.
I think the idea is that ancient people weren't able to really contextualize the past. That's a hard thing to envision until you look around and realize people today have a hard time with it too. It helps to realize when they talk about anachronism it's not just the simple ones like a clock tower ringing out in Shakespeare's Julius Caesar. You might see it on this very sub when people ask questions that are informed by modern thinking and lifestyles but don't really make sense in the context of the past. I wish I had a good example on hand to dig up, I kinda know it when I see it (and like I said the subject feels just out of reach of my brain). And those aren't necessarily "bad" questions, often the answers can be particularly enlightening.
Edit: to clarify the book I bought is Birth of the Past by Zachary Schiffman