Traces of the same spiritual concepts and symbolism that enlighten the Egyptian texts are found all around the world among cultures that we can be ce… - Graham Hancock

The Younger Dryas impacts, and subsequent sustained cataclysm, changed the face of the earth completely and wrought particularly significant havoc across North America. We have considered the question of huge volumes of meltwater released into the Arctic and Atlantic Oceans from the destabilized ice sheet and looked at the effects on global climate. But keep in mind that those enormous floods also devastated the rich North American mainland to the south, perhaps the best and most bounteous real estate then available anywhere.
This immense and extraordinary deluge, 'possibly the largest flood in the history of the world,' swept away and utterly demolished everything that lay in its path. Jostling with icebergs, choked by whole forests ripped up by their roots, turbulent with mud and boulders swirling in the depths of the current, what the deluge left behind can still be seen in something of its raw form in the Channeled Scablands of the state of Washington today — a devastated blank slate [...] littered with 10,000-ton 'glacial erratics,' immense fossilized waterfalls, and 'current ripples' hundreds of feet long and dozens of feet high.
If there were cities there, before the deluge, they would be gone.
If there was any evidence of anything that we would recognize as technology there, before the deluge, it would be gone.

Not for the first time I felt myself confronted by the dizzying possibility that an entire episode in the story of mankind might have been forgotten. Indeed it seemed to me then, as I overlooked the mathematical city of the gods from the summit of the Pyramid of the Moon, that our species could have been afflicted with some terrible amnesia and that the dark period so blithely and dismissively referred to as `prehistory' might turn out to conceal unimagined truths about our own past. What is prehistory, after all, if not a time forgotten — a time for which we have no records? What is prehistory if not an epoch of impenetrable obscurity through which our ancestors passed but about which we have no conscious remembrance? It was out of this epoch of obscurity, configured in mathematical code along astronomical and geodetic lines, that Teotihuacan with all its riddles was sent down to us. And out of that same epoch came the great Olmec sculptures, the inexplicably precise and accurate calendar the Mayans inherited from their predecessors, the inscrutable geoglyphs of Nazca, the mysterious Andean city of Tiahuanaco ... and so many other marvels of which we do not know the provenance. It is almost as though we have awakened into the daylight of history from a long and troubled sleep, and yet continue to be disturbed by the faint but haunting echoes of our dreams

A dominant individual, with a prestigious position, can delay the progress of knowledge for decades but ultimately cannot stop the buildup of contrary evidence and opinions that will lead to a new paradigm.