I got hit hard by a wall once. I was chasing my kid brother, and when he jumped out of the way just before I tackled him, I smashed into the wall really hard. All day long, my neck hurt, and by the afternoon I noticed from my shadow on the ground that my head was cocked at a right angle to my body. For years, my jaw clicked from that impact.
I once had a girlfriend who got hit in the head by a flying block of ice at a football game. It knocked her out, and afterwords she suffered periodic fainting spells. She'd be fine, and then just fold up and collapse to the ground. I had to carry smelling salts to revive her, which she hated. She would be really weak afterwords for a few minutes, and sometimes I had to carry her. Once, I had to carry her five blocks to the car after a movie. People thought she was drunk!
Another time, while parked on Molholland Drive admiring the lights of LA, she passed out a hundred feet from the car. I picked her up and started walking back. A squad car pulled up, and the cops jumped out. "Put the girl down and get down on the ground right now!" I guess it looked just a tad suspicious.