I have a lot because in elementary school I had major anxiety problems, especially towards the end because the medication I was trying at the time made me more aggressive.
I don't feel comfortable sharing any of those though.
However in second grade one day, I was wearing pants that were too big for me, and when recess came along I ended up tripping and the fell off. I was also wearing spongebob underwear at the time.
This one isn't really embarrassing to me, but I'll share it anyway. In 8th grade I was walking into school wearing a new pair of jeans, and my mom yelled out of her car window that I had a sticker on my pants. I felt around to find a sticker on my right buttock that said "New fit!"
Also this isn't that relevant, but in grade seven, someone got expelled for pushing my friend Duncan down a stairwell and splitting his ear open.