For several centuries after the Western empire fell apart, Europeans lacked the capability to build settlements or structures anywhere close to the size typical of classical Roman civilization. Populations were depressed by pestilence, social order had declined, and most Europeans were within a short distance from a former Roman settlement of a size larger than they'd ever seen populated in their lives. The Eastern empire was a little different, but Western Europe was pretty much fubar in the early middle ages.
Although technology steadily progressed throughout the middle ages, it took centuries for population and social organization to return to anywhere near classical levels. If you lived during the early middle age, it was an unmistakable fact that a great "precursor civilization" capable of wonders far beyond what your own civilization was capable of had lived and fallen long before you were born. With colossal roman ruins scattered across Europe, there was no need to look to the bronze age for a fallen civilization.
Compare to what Xenophon saw at Nineveh: A city wall 7.5 miles circumference, made of stone and brick, 55' tall and up to 50' thick. The most impressive structures he would have ever seen - just out in the middle of nowhere, absolutely abandoned.
https://www.amazon.co.uk/Landmark-Xenophons-Anabasis-Shane-B...
Beautiful book with lots of maps and illustrations covering the journey mentioned above, if that’s anyone’s bag.
I don't think people realize how far ahead of everyone else Rome was at that time.
Like most people know that Rome had aqueducts bringing in water to the city, but they probably don't know that water was supplied to different buildings directly, and you could pay to get a line installed straight to your house. Running water in your house, 2000 years ago!
TLDR; people considered themselves "Roman", or something adjacent to it, long after the western empire officially disintegrated, and of course in the east it didn't really die.
Even on the outskirts (e.g. Romano-British) people held onto Roman, Christian, and Latin culture at a very deep level. And even when the Anglo-Saxons invaded they were extremely aware of who and what the Roman ruins etc. were, even if they chose not to settle in them in many cases.
Three of the 10 most common languages on Earth boil down to "Latin with a bad accent".
I don't think there's a real timeline where Europeans were wandering around the ruins of the suddenly collapsed empire wondering who these people were. They knew fully, but the economic and political (and physical! plague!) situation meant they were unable to reconstruct the Pax Romana.
But they certainly tried, even when they were former "outsiders" like the Franks (who, in the west half of their realm, even dropped their native tongue to speak a form of Latin!).
In fact I feel it's possible that actual "progress" wasn't possible in Europe until philosophical thought moved beyond late-Roman neo-Platonic & neo-Aristotelian boundaries, and into new radical enlightenment era concepts.
Eventually we did remake the Pax Romana, but it took two utterly ruinous wars, humanism, and a working knowledge of free trade to recreate the system that Rome had managed to create almost by accident.
I'd posit that today's world is what it is because it is partially on built enlightenment values that stepped away from the old Roman model, not back to it.
Reproducing the previous society is the mistake, because it wasn’t just the society. It was the free trade and lack of Mediterranean piracy that brought prosperity. The relatively increased civil rights that brought stability, and Senate that brought legitimacy. They had a model that produced the best economy and civil rights for their era, but looking backwards to past glories can’t replicate that.
https://brill.com/view/journals/joah/4/1-2/article-p28_4.xml
Putin simply sees himself as the new Tzar, and by extension master of the lands of the Third Rome, i.e. the Baltics, Ukraine, et al.
When Roman power in the West collapsed, and, for example, the remaining population of Arles retreated into the amphitheater of their previously much greater and more prosperous city, building a fortification in the middle and from the ruins of what used to be before, there were almost certainly people among them who could recite Hesiod. I just for some reason find this so trippy.
I base this only on finding the trope of "precursor civilisation/society with the best tech" in literature from across the globe.