I found this a fascinating bit of research. I suspect that there is so much of our history undocumented, with only remnants like those described as a window to that past.
This includes almost all ordinary peoples lives, but also things like the childhood of people like Charlemagne.
We do know all kinds of things about ordinary people's lives based on physical evidence in archeology; we can figure out what they ate and where they got that, what jobs they did and how they organized that, what health issues they had and how they died.