OK I'll bite and throw out a few more hypotheses of what would really freak most people out.
a) We live under a dome. The earth's surface is actually a flat disc with an engineered artificial support structure far beneath. There are other realms on portions of the disc outside of the dome/ Antarctic ice wall.
b) Human beings were created by an alien species via DNA manipulation of earthly animals. The reveal is both of the alien species that has been calling the shots here, and that humanity and all the plants/ domestic animals we depend on were created in an artificial manner.
c) The historic timeline we have been told is completely false. Previous eras of high tech civilization existed on earth and were washed away by successive floods, caused by cosmic forces such as the earth periodically passing through an enhanced cosmic radiation zone.
d) Humanity has long possessed electrogravitic technology that can power flying craft capable of traveling unimaginable speeds and unimaginable distances quickly. There have long been human colonies on other distant bodies/locations of a "breakaway civilization" that has been ripping off the rest of humanity and stealing trillions of dollars from defense budgets.
e) The earth is riddled with tunnels interconnecting all the major human civilizations. Wars are fought in these tunnels, which are also provisioned by elites for their continued existence (and our demise) in the event of major warfare on the surface or other catastrophic happenings.
f) The appearance of different countries being enemies or friends is completely fake. The truth is something completely different.
g) Our minds and bodies are controlled by nanobots which we cannot possibly avoid ingesting/inhaling. Only a few people are able to break away from being controlled by these things. Their removal/disablement will cause the majority of humanity to die off. The survivors will have to start a new civilization from the ground up.
g) There were giants in those days. Remnants of giants, of all different sizes ranging from 10 feet to hundreds of feet or even miles high, are found all over the earth, as well as buildings and artifacts made by those giants in their day.
h) Aliens/extraterrestrials/giants still exist in a state of suspended animation on Antarctica. They had advanced technology far beyond anything we can imagine. Human explorers have awakened this technology and know how to reawaken the giants/ETs. Governments are colluding to keep the evidence concealed and are fighting over exploitation of this high tech.
I could go on………..