Some people believe there have been five major civilizations before this one. All wiped out by global catastrophes, forcing survivors to start from scratch.

Any body giving a number is full of shit…

But, statistically speaking, we’re almost certainly not the first human civilization. Modern humans are pretty identical to humans 300k years ago. And while people say we needed the thaw of an ice age, we went thru several cycles over that 300k years.

Now, if any of them surpassed us or not, who the fuck knows. Probably not.

But even at our current level, 10-20k years is all it would take to erase pretty much all the evidence we existed. Even stuff like Mount Rushmore would eventually wear away to the point people might say “that kind of looks like a couple faces” and be written off as coincidence.