Figure this thread is a good enough place to say this:
If you watch Ancient Aliens, they would have you believe that every un-explained phenomenon must have occurred with alien help. But I have another theory that may also explain the so called ‘cave man’: As a rule, every generation think they are smarter than the last. But with all the high-tech relics found on earth over the years, structures built to mathematical perfection for no apparent reason, I am a believer that something happened in human history (when they were much more advanced than we think) so cataclysmic that a good deal of our history is simply... missing.
It would make sense if you think that those who may have survived that cataclysmic event were so busy surviving, there wasn’t time to write down the details of what happened. but it could have been something like a polar magnetic shift. Could have caused the Great Flood perhaps?
Just my $.02
There was an antediluvian civilization, much of which has been lost to history.