Well, we actually know that humans have gotten significantly more intelligent over the past thousand years. There's something to be really proud about that a civilization could construct a literal ancient wonder like the pyramids at Giza. It's kind of fucking stellar. The level of organization, sophistication, attention to detail, and ingenuity to create such things is utterly mammoth. I think the only thing comparable in modern times would be things like Particle Accelerators and the entire US Highway system.