Michael Dell — Dell Technologies

Dell dropped out of the University of Texas at Austin at 19 after his dorm-room computer business was generating $80,000 a month. Dell Technologies is now worth $100+ billion. He took the company private in 2013 for $24.9 billion (the largest tech buyout at the time), restructured it, took it public again, and emerged wealthier than ever. His net worth sits at $120 billion. The UT Austin dorm where he built his first PCs should honestly have a plaque. Instead, they probably converted it to a study lounge.