When I attended college, it was assumed you were either adult, or very nearly so.
It has been discussed quite a bit how adulthood is now on a delayed-entry schedule. I speak about adolescents in their 30s, for instance.
This is a proof of that idea, since the system of recording insults seems like what a middle-school teacher might use, to make a point.
So think of high schoolers, as elementary children. Think of the college to 30s aged category, as middle schoolers, and you won't be off by much.
I learned to not sass my fellows on construction sites and docks, as a teenager.