I imagine for the early people on our rock, the change of seasons and the movement of the sun, moon and stars across the sky really was quite scary.
No one told them not to stare in the sun, at least not formally, they just somehow knew - maybe through experience, that it was a bad idea.
No sunscreen but I suppose sufficient quantity of mud and leaves provided a high enough SPF level to prevent burns on some.
Meanwhile, the sun seemingly flopped back and fourth through the sky day after day, unaware that the silly people on the 3rd planet had anthropomorphized it into some kind of vengeful deity that was hungry for sacrifice.
What's a giant plasma ball of hydrogen and helium gonna do?