are what real adults stop using when they really mature
I read a book awhile back called "The Disappearance of Childhood". 40 years ago It talked about how the division between childhood and adult was being eroded as kids were exposed to adult movies, images, ideas and worries at earlier and earlier ages. Even then he noted we were losing the innocence of youth.
I know 1st grade teachers who have students that have seen all the saw movies. I saw a billboard aimed at kids asking them what their plan for a natural disaster was.
My theory is that we used to have age levels where kids gained more responsibilities and along with those more freedom. The kids looked forward to those milestones where they could stay up later, get a job and thus money, get a driver's license and thus freedom, watch movies that were edgier, move out, have a family... They aspired to be older and more mature because each step involved a freedom they didn't have before and the responsibilities that came along with that were worth it.
For many now, they don't have to wait or work for any of that. At very young ages they can already watch what they want, they get driven everywhere, they get money for whatever they want. There is nothing they are lacking that being more mature would get them, so they don't bother. Why take on responsibilities if they don't get you any new freedoms?