You ever read a post, and then wonder about the posters life? What led them to think this way? What happened? What are people around them like? What media do they consume?

OP are you ok?

(are you ok OP?)

Calling an adult a child is observing that they're exhibiting immature behaviors most often seen in children. Your post is a very good example of an immature thought.

Sometimes I'll say something in adult company that unintentionally reveals a lot about how I was raised. Usually accompanied by concerned looks and awkward silences.

I think this may have just happened to you OP. That's not a common way to see children.

An adult being called a child is only an insult because people are supposed to gain some maturity as adults. Do most think a child is bad because they cry when they get told no? No, because that's part of being a child - they have to learn. If you do that same thing at 20, it's a different deal. It's not that children are bad, it's that you should grow out of some things when you're older. In fact, sometimes people refer to a person as "child-like" as a compliment, but would use "childish" as an insult. Children are prioritized in the US pretty highly.

Tired: children are seen as livestock to some

Wired: children are seen as pets or trophies to some

Inspired: CHILDREN ARE NATURE MANIFEST!

I, speaking only for myself, hate children because they're loud, filthy, and annoying.

only a child would think this way

While your premises may be true, I'm not sure the conclusion follows.

An extension to this is so many of us in the US don't seem to understand that we are still the children we were. You develop new parts of yourself, gain new perspectives, new habits, etc, but the reason you remember the insurance company is the same reason that little kid can hum the whole jingle.