Phineas Gage, an American railroad construction foreman, was a very calm and respected leader. He was one to break up fights among his crew and lead them in making good decisions.
One day, while at work, a terrible accident happened to Phineas while they were blasting rock. A metal rod, weighing 13 pounds, went into his left cheek and out through his forehead. Miraculously, Phineas survived!
Although he survived, the accident caused him to loose sight in his left eye and act like a child. Phineas died twelve years later because of seizures related to his accident. Because of this accident we know a lot more about brain science. If this accident would not have happened we might not know half the stuff we know about brain science today.