[fedeb95]

knowing how it works, meaning what it does, doesn't always imply knowing its inner details. Its the basis of abstraction.

[bsza]

Abstraction isn't ignorance, it's the very conscious choice not to depend on implementation details. Being ignorant to those details doesn't give you any superpowers, abstraction itself does. It doesn't work because you don't know everything, it works despite that. Not knowing everything is still a bad thing, we just find ways to make it less bad.