Actually, I think kids get it more than we give them credit for. The goal isn't for them to walk away with a rule book, you know? When I showed my nephew, his big takeaway was just that metal makes a loud 'clang' and it's heavier than it looks. That's a win. Understanding builds from those little moments, not from a perfect lecture.
My neighbor's kid, Sam, learned about gravity by dropping his juice box. The splash was a bigger lesson than any diagram. Adults do the same thing. We remember passwords after forgetting them once, not from the security tips. Real understanding comes from doing, not hearing.