A little bit of both actually. I honsetly do believe that there was a time in the past where human beings developed technology that most archeologists don't want to admit that they had.
Any engineer will tell you that we couldn't build duplications of the Egyptian pyramids today... certainly not with the precision that they were built. There are man-made structures on the floor of the ocean off of the coast of Japan, and off the coast of the Bahamas that are deep enough, that the last time that the ocean level was low enough for people to build there was literally thousands of years before mankind was even supposed to have the technology to build like that.
Also, ancient man had knowledge of the universe that would literally be impossible to know unless they had the technical knowledge to find out. There are ancient accounts in Indian and Summerian texts that describe what the Earth looks like from space. The Old Testament talks about the early universe being formless, and there being no light or dark... well, the study of physics tells us that the early universe was devoid of form and that the universe was opaque, so there was no true deliniation between light and dark... at least not in the way that we have today. Ancient Native American legends (from North and South America) talk about the Gods having the power to warp time and space to create gateways to other worlds (in my campaign they were superhumans traveling to and from the Imageria).
The Mahabarata tells the story of a city that was destroyed in fire by a terrible weapon that generated such a large conflagration, that all of the structures were in ruins, and all of the people died. After the fire went out, people that went into the area came back with horrible burns, their hair fell out, and they died. Well, in the exact spot that the writing says that the city was, the ruins of an ancient city were found in the jungles of India... and there is ample evidence of the city being destroyed by fire, the people flash-fried to death, soil-vitrification, and radiation levels much higher than they should be.
So, for my campaign, I took my borderline-obsession with my wild theories on ancient man, and the concepts from the Paragons book, and threw them together to make a cohesive world with a solid background that is a mirror of the real world... but much more weird.
A superhuman war caused the destruction of a powerful, advanced society (something else that has been alluded to in nearly every single ancient religion on the planet), and all of the survivors were thrown back to the stone-age. As they began to rebuild the foundations of civilization, the breakouts started happening again, and mankind started growing in both size and technological know-how in leaps and bounds. Over time, one man here or there had a breakout that drew a large portion of the population into one cohesive nation... so that even after their deaths, their accomplishments drove development of human civilization toward a specific destination.
When the Dark Ages happened following the fall of Rome, King Arthur broke out and drew the British Isles together into a nation that would one day become one of the most powerful empires the world had ever seen... and in turn, Major George Washington, when facing defeat by the French at the Battle of the Monongahela, had a breakout in the early stages of the French and Indian War, set the stage for a group of British Colonies to rise up into yet another powerful nation... a nation that was solidified as an almost unparalleled world power when Adolf Hitler had a breakout and caused one of the most horrible and violent conflicts in the whole of human history, and the United States and their Allies stopped the Axis expansion.
But now, the world is at the height of social, racial, economic, and political tensions. The mass introduction of superhumans to the world has the potential of sparking a war the likes of which have not been seen in the whole of recorded history... because now they have to deal with individual people that have personal power that rivals that of entire nations.
Even in a lower powered setting like mine (PL 10 is the MAX for PCs, and none of my PCs are there yet), a man that is bulletproof and can throw a car is all but unstoppable to normal law enforcement. A group of people with that kind of power could literally upset an entire nation if they worked in unison. Imagine a paranormal with the power to be as charasmatic as Adolf Hitler, surrounded by a group of PL8-10 paranormals, who founded a cult where they were worshipped as gods... now imagine that same group, and all of their followers (potentially numbering in the thousands considering the rank of the power) overthrowing security at a facility that handles nuclear weapons. Imagine a terrorist with Quicksilver's speed possessing an expertise with demolitions... or a "suicide-bomber" that is invulnerable, so that he can repeatedly strap himself with explosives, detonate, and simply walk away. Or worse yet, a teleporter who detonates bombs at a hidden location and simply teleports the detonations into public buildings and crowded intersections.
I try my best to make my badguys very, VERY frightening. I want my PCs to feel like their characters are operating on a level where every single move they make directly impacts the world. The paranormals that strive to be true heroes are the only thing standing between humanity and extinction.