TIFU by accidentally dislocating my sister's nose.
Back when I was like 14 or 15 and going through puberty I didn't get how strong I was getting yet. I would open the door that led to the garage with my shoulder using all my strength cause it was a fully metal door and id pretend to be a military commando or something, IDK I was a really dumb kid.
Anyways one day I was going out to the garage for something and used all my strength to open the door like I always did. Just for my sister's luck she was right by the garage door as I was opening it as hard and fast as I could the door swung open and slammed right into her face. Before I could even recognize what happened I hear a thud and she's on the floor blood gushing out. She yelled at me and said something like "WHAT THE FUCK IS WRONG WITH YOU???" In a perfect bugs bunny impersonation. I was scared shitless and ran to get my oldest sister who was the only other person in the house who could drive at the time. We all rushed to the ER and I had to call my stepdad who was non too pleased about the story to say the least.
At the ER it was found out that her nose was dislocated along with her having a black eye and she had to wear this brace looking thing that looked like an elephant trunk. All in all she was fine but her nose has a slight tilt to it now and I always do feel a little bad when I remember.
TL;DR:Me not knowing how strong I was getting as a teen accidentally dislocated my sister's nose