Probably because people did live in the dark much more than we do today, the senses were enhanced by our standard. Just as blind people learn to navigate in darkness so would most anyone brought up in those circumstances .
I have read of ancient batteries , it's entirely possible that solar power was utilised, maybe not as we know it today though .
There are ancient dew catching structures for water supply in arid regions , the Angkor Wat technologies -- even the seafaring technologies employed in the distant past show that technologies don't have to be like our modern ones to actually work.
From what I understand, much of what we used to know has been deliberately destroyed or lost thru warfare .
Thats probably why we are heathens today, because we know there were societies in the past that really had it together that were destroyed by natural forces.
The Minoans I think it was were much more sophisticated than surrounding cultures until they got blown away by a volcano
