Why is that amusing to you?

Americentrism. America discovers that water is wet and suddenly out come the flags and eagles

If something hasn't happened in your area before, it is new to the experiencer regardless of it having occurred elsewhere. If an area experiences a flash flood are you likewise amused by their exasperation at the novelty of their situation, despite it having occurred to plenty of other people in other places?

That makes sense. Those other places don't actually matter, but America does.

Can't even understand whether you're being ironic or not.

They matter, but not like in the sense that Americans should care about them.