There are currently many cultic belief systems that revere ancients as if they were far superior to modern humans in knowledge and intelligence. How else could they believe that Mayans had predicted the end of the earth? All those humans from prehistory were somehow more sensitive to their surroundings and closer to their "gods". Never mind the fact that they thought the earth was surrounded by a crystal bowl, they knew more than we do about the heavens.
This attitude isn't limited to religion. It's the basis for many conspiracy theories and "ancient aliens" stories. What are we missing that the ancients knew? According to some, they knew more on just about everything.
With all that knowledge, one would think they'd have a sophisticated written language to record it (missing from Mayans. The Egyptians had a good written language, and told us all about some things including what they ate and who had affairs with whom, but forgot to record all their scientific discoveries. Go figure.) They didn't even invent the printing press for gosh sakes.
Another interesting concept is how technology stories grow with time. Metals and alloys are an example. The term 'Damascus steel' has a mystic ring to it, and it's true that for a time, blades from Damascus were among the best in the ancient world, but their uniformity and performance do not approach modern commercial steels. I think this is in part because the term 'we don't really know how they did it' gets mistranslated into 'they did something beyond our technology'. Not true.
For a time, there was a steel making culture in ancient sub Saharan Africa. This is another example of a significant technological advance (for the time) being reinterpreted as a nearly mystical technology. Their process worked, but it produced a hodgepodge of clumps of metal, some of which had, by chance a proper carbon content. These were the ones that were used.
Whether you're talking Damascus, or Feudal Japan, some wonderful technologies developed, but none of these have 'put modern technology to shame'. They got some good results, but had no idea why and could not reliably recreate the results. Hence the pieces that happened to be superb acquired a mystical reputation (Excalibur).
Excellent analysis! It would be almost as if monkeys at keyboards really did reproduce one of Shakespeare's sonnets, and then had no idea how it happened. Ha!
Lots of ancient knowledge was lost during disasters such as the burning of the library at Alexandria or when advanced civilisations fell. Much of that was not rediscovered, probably because of different priorities of subsequent cultures or inventors not having the same ideas.
Lost knowledge doesn't equate to superior knowledge - modern technology can do the same things as ancient technology but more effectively. Finding out how they did it without modern technology is mostly a matter of curiousity, not a way to unlock methods superior to modern ones.
There is also the psychological aspect of distant knowledge being more mysterious and therefore more appealing. This is why many westerners are drawn to eastern religion (and vice versa). Magic tricks are more appealing when you don't know how they are done.