A friend of mine, Brad, is called Hammerhead. Why? He's a great guy, not the brightest in the world

Anyways, he grew up on a farm and had gotten into lots of accidents using the equipment or just through pure stupidity. He said he had gotten at least 20 concussions in his childhood. Because of this, he unfortunately can no feel anything in his head.

Literally. At the summer camp we worked at, an iron pot fell on Brad's head, and he didn't know it hit him. He heard it hit the ground, but had no idea it bounced off his head. It was pretty funny at first, but very scary that he couldn't feel anything in his head.

Anyways, the word got out at the camp that he couldn't feel anything in his head, and lots of people called bullshit on it. So one day, we demonstrated how he couldn't feel anything. I dropped a iron pot on his head again an he didn't even react. He also took boards and smashed them on his forehead, and would break them with a smile on his face. It was a spectacle demonstrating his superhuman power.

Anyways, most of the people we worked with was amazed and believed how he couldn't feel pain in his head, but a girl we worked with didn't believe it still. Brad had a crush at the girl at the time, and was motivated to make this girl believe. So you know what the fucker did? He took a hammer out from the warehouse, and began to smash his head with it.

It was terrifying. Horrid. I couldn't believe he was doing it. He smashed it violently. The thuds hitting his head were so loud, and the girl was crying. Brad stopped, and smiled at her. He then said, "Yup, couldn't feel that at all." We were all stunned, and no one said anything. Then the side of his head started bleeding furiously, and I ran to get a first aid kit.

I remember saying, "The fuck were you thinking?!" and "Are you positive you're alright?" and "How the hell didn't you feel that?". He still smiled, and so forth.

Next morning, Brad is screaming in pain for he has the worst headache of his life. He's vomiting everywhere, and we had to tell our boss about what the hell happened yesterday. The camp medic examined his head, and sent him to the hospital right away. Brad had a major concussion, a cracked skull, and possibly serious brain damage.

Anyways, poor Brad was in the hospital for a month an a half, and got out with (happily) no permanent brain damage. He had to get plates (or what ever the fuck they are) in his head. But after he got out of the hospital, he still says he never felt the hammer smashing into his head, and that he said he still couldn't feel anything in his head.

That day forward, even if he was being a really good fucking lair or not, we called him Hammerhead after that tremendous spectacle he pulled off. He doesn't like it, but you don't choose your nickname, you're given it. The girl he smashed his head for ended up dating Brad later, and they dated for two years until Brad did something stupid. Even she called him Hammerhead when they were dating.

tl;dr : Friend of mine that can't feel anything in his head smashed his head with a hammer to impress a girl. He goes to the hospital and given the name Hammerhead