Our historical record of pre-500AD is kinda crappy and put
   together.

   We don't know that we're better than pre-500AD "measurably". We
   have limited information about life in those times. Much of the
   historical testimony is plausible fiction, not historical fact.

   I'm glad to be living today in 2015, but it's likely I would've
   done just fine in Ancient Greece, or Rome in its heydey. I
   wouldn't know any better, just as I don't know what I'm missing
   by not being alive at 2500AD. Our limitations are bound to the
   eras we find ourselves in.

   and 2500 AD is only 400+ years ago. Not that far away.