Amazing. I've been asking myself the question for a long time. What bothered me about our existence is that what makes us so great that in the last 150 yrs. We are able to invent the bicycle, car, train, electricity, telecommunications, computers etc... And no one in the past history of mankind was able to think of these technologies. Surely someone had to witness lightning and wondered how they could harness it. I just don't believe that we were the only smart people ever to exist and the ancient sites proves just that. Someone kept us in the dark for there own personal gain I think.