Ok: After seeing many people robbed beaten and killed, he decided to invest in some defense. He thought on what to do, finally asked a family friend on how to make knives, he decided to teach him: where to find rebar and a decent sharp metal in the scrapyard, he taught him how to sharpen his blade and weld it to a nice handle/more metal. He kept this knowledge and still practices making shivs today. (Nothing else i can add really, )