So instead, he started his to start with tech enterprise, which built him a millionaire by age 28. Then he started off yet another company - and one more - amassing hundreds of thousands and then billions of pounds in prosperity along the way. Hemenway, David. "The Myth of Millions of Annual Self-Defense Gun Uses." Chance. Krouse, William J. "Gun Control Legislation." Congressional Research Service. Koper, Christopher S.