It is possible change your behavior & personality?

On September 13, 1848, Phineas Gage, a 25-year-old foreman on a Vermont railroad construction crew, was using dynamite to blast away rock and dirt. Suddenly, an unplanned explosion almost took Gage's head off, sending a 3 1/2-foot-long, 13-pound metal rod under his left cheekbone and out through the top of his skull.
Much of the brain tissue in Gage's frontal lobe was torn away, along with flesh, pieces of his skull, and other bone fragments. This should have been the end of Phineas Gage, but it wasn't. He regain consciousness within a few minutes and was loaded onto a cart and wheeled to his hotel nearly a mile away. He got out of the cart with a little help, walked up the stairs, entered his room, and walked to his bed. He was still conscious when the doctor arrived nearly 2 hours later.

Although Gage recovered in about 5 weeks, he was not the same man. Before the accident, he was described as a hard worker who was polite, dependable, and well liked. But the new Phineas Gage, without part of his frontal lobe, was loud-mouthed and profane, rude and impulsive and contemptuous of others. He no longer planned realistically for the future and was no longer motivated and industrious, as he once had been. As result, Gage lost his job as foreman and end up joining P.T. Barnum circus as a sideshow exhibit at carnivals and country fairs. (Adapted from Harlow, 1848.)