Humanity has somehow managed to count up to 2019. That doesn't sound too impressive, but have you ever tried to count thousands of things without losing count even once? Try counting the number of grains of rice in your bowl next time you have a rice dish.
@starkatt We had heard of that, but had forgotten.
I think it would be very difficult to fake a millennium of events, though. Especially because it would require a worldwide conspiracy to have happened before there was much worldwide communication.
@Rosemary Have you heard of the conspiracy theory that the Middle Ages never happened? https://en.wikipedia.org/wiki/Phantom_time_hypothesis