I am 6’4". When I was in high school still living with my parents, my mother would call me for dinner and I would come running to the dining room. This was the routine every day. Get called for dinner, bound down the hallway to the dining room like the devil was chasing me, sit down and eat. Get called for dinner, bound down the hall-OWWWWW!!! OWWWWW!!! WHAT THE FUCK WAS THAT!!!
I sank to my knees on the floor holding my head and waiting for the stars to stop spinning around me. Apparently over the course of one day, I grew enough that I no longer had clearance under the door frame while running at full sprint. I hit my head so hard it bled.