> Afterwards they are divided between little geniuses going into „Gymnsasium“, average ones going to „Realschule“ and good-for-nothings going to „Mittelschule“.

I would totally land in Realschule because I had an educational slump in fourth grade.

Over here they tried a similar system - middle school spanning classes 7-9 inclusively, named "Gymnsasium" as well, but it included everyone[0] and I recall having a similar sentiment, thinking: "why shove people around like that? So that we don't form lasting friendships and thus make better worker drones?"

Ironically I'm still in touch weekly with the three guys who were my only friends at the time, even though we live in different cities now.

[0] The split between college material and the rest only happened around high school.