Phineas Gage was a well mannered man and a good leader. Until his accident. When he wasn't paying attention, gunpowder exploded and sent a three and a half foot tamping iron through his left cheekbone, into his brain, and out his skull. The tamping iron landed thirty yards away, but Phineas acted strangely normal.
Gage was rushed into town to be seen by a doctor. He sat on the steps of a hotel and waited for the doctor. When Doctor Harlow showed up Phineas was happily chatting with citizens about the accident. He famously told Doctor Harlow "Here is work enough for you". He got an infection and his chances of living were low but Gage came out alive.
Ten weeks later Doctor Harlow was confident enough to set Phineas free, but he would never be the same again. He wanted to work again so he went back to his old job as a foreman, but Phineas would constantly give bad orders, contradict himself and lose his temper. He eventually got fired and eleven years later he died from lasting affects of the accident.