A 28-year-old man from Shenzhen, China had suffered from terrible headaches his whole life. As they became more intense and frequent, he finally visited a doctor at the Shenzhen University General Hospital. An MRI revealed a metal pellet lodged in his skull that the fellow never knew was there. From Oddity Central:
Interestingly, Chen remembered that when he was about 8-years-old, he and his brother were playing with an air gun at home, when the gun accidentally went off, shooting him in the side of the head. He and his brother were afraid of being scolded by their parents, so they didn't say a thing, and the wound was covered up by his hair, so the parents couldn't really see it. Plus, the wound wasn't too painful, so he eventually forgot about it.
Surgeons removed the projectile and the man is reportedly recovering at home.