“...why don’t I act like one?”
Who says you don’t? Go watch a bunch of high school kids at lunch or just hanging out. You can see the resemblance.
Children act as they are allowed to act, the two of yours that I met would have lost their scalps if they crossed the line? The thing that bothers me is human kids require 13 years to develop into PIAes, in all of human history we have imposed very strict limits on their behavior, as in take swing at the Old Man or Lady a short walk to long drop.
This type of control is exhibited in no other animal nor is the time reach maturity.
Rack time.