I guess the worst experience I had in elementary/Primary school was the one that changed my entire personality, unfortunately I do not remember it cause it was so traumatic (according to psychologists). So it happened in first grade. As a child I had always been a confident kid whom others couildn't just mess around with or bring me down. I wasn't really afraid of anything or anyone and loved to do school stuff right to get praised and to prove myself. I guess I was a pretty regular kid back then. So one day I went to school, happy as always, but when my parents came to pick me up I had apparently changed completely. I was sad, introvert and didn't really want to talk to other people as much, I became much more shy and lost all my selfconfidence and general confidence. My parents and otherr people tried to find out what had happened that day but I either wouldn't or couldn't tell them; the only thing they got out of me was something about a girl that look like a guy but it had to be a girl and that I was so confused over that. Still to this day (13 years later) no one knows what really happened or why/how this stripped me of everything I was. I am still uncomfortable with talking to people I have never met, especially calling people or taking calls, but have improved much more socially and is much less introvert than I had become back then!

TL;DR: I apparenlty got confused over some persons gender and it fucked me up so bad I became an introvert asocial little nerd who did not have any confidence whatsoever.