The Sigmund S. Freud Middle School
Middle school is where Freud's reality principle kicks in with a special malevolence and you realize that--despite what you may have previously heard--you really can't become whatever you want to be. If you have always sucked at sports or math, it's very likely you will continue to suck at sports or math. If you are shy or geeky, these traits will only be exacerbated by age. Consequently, that future affair with a honey-haired Farah Fawcett isn't really in the cards for you. You may as well accept that now.
Middle school is also when any remaining childhood neotony resolves itself into one's own unique catalog of physical demerits. I actually remember a boy in junior high who was balding by the end of eighth grade. It was as if some hormonal dial had been set too high and hurled him from middle school straight into middle age.
I've tried to prepare my son for this transition by telling him that almost everything he will experience over the next three years is nonsense and doesn't apply to the rest of his life. I've even let him watch a few episodes of The Wonder Years and Freaks and Geeks on Netflix. Unfortunately, despite their occasional cynicism and honesty, these shows usually wimp out with small, redemptive endings. Even they can't fully face the reality principle of middle school: the pretence of unformed potential is over.
What really haunts me is something my grandfather said near the end of his life. His last few years were spent in an assisted living center. One day while complaining about the place, he said it was just like having to go back to junior high after a lifetime of being an adult.
Sent a chill, I can tell you that.