Why is it always a surprise that prehistoric humans were smart?

Seriously, it seems like every headline comes like a shock: Easter Islanders could navigate to the continent! (Who knew?) Ancient Greeks had clockwork calculating machines! (How could they possibly?)

11,000 years ago, humans had culture and rituals... what did you think before this, that they just wandered around, hoping that food would fall out of the sky? Maybe if we go over there, a magical being will tell us how to make fire?