Learning.
Humans rely upon adults to teach their young what is to be feared and what isn't.
Humans are born with a fear of loud noises, a fear of falling, and only one or two other fears, otherwise are fearless.
That doesn't mean there aren't dangers - it's that for the species to survive the parents have to teach and protect.
Arf
There weren't any snow leopards in my neighborhood when I was growing up. Wouldn't have been afraid of them.
Arf