The question occasionally comes up around this idea of past golden ages – if its true, why isn’t there more archaeological evidence? Well, for one thing, because we’ve not looked for it. Science would not fund such research. It doesn’t fit the model. Aside from some conjectural stuff like “Chariots of the Gods” in the ’60’s, there is little widespread knowledge of the distant past. Yet there is ample evidence of megalithic structures all over the world. Certainly, the pyramids are best known, but these also exist in China, Japan, Mexico, and more. And they notably have similar group alignments. There are structures in Egypt that even today engineers are not capable of erecting. And the story of how the pyramids were built is hogwash. Palm trees cannot support weight, no mater how many slaves you add.
Another factor is earth changes. The exact fitting structures off Bermuda and Japan now sit in the ocean. Time and entropy destroy a great deal of evidence. But there are also very old texts that are sparsely translated with detailed instructions for building flying machines, navigational instruments and more. The Vimanas of India, for example.
Of course there are lots of theories and ideas about what we don’t know. Humans are great for taking what is known and projecting it into the trash. But there is one trend that seems obvious on reflection.
The hardware stage of technology lasts just a few hundred years. At a certain point, discoveries are made on how to work with energy and forces more directly. Less hardware is required, thus less evidence. Further along, knowledge of consciousness expands into the “siddhi” range and we learn to do simply with awareness.
As a result, the ravages of time and the earth and the folly of man (such as burning the library at Alexandria) leave little evidence for the brief and passing hardware phase. The one we’re in.