A college drop-out, the founder of Oracle is now one of the wealthiest men in the world.

Born to a teenage single mom in New York City who was unable to care for him, Ellison was adopted by relatives when he was still a toddler and moved to the south side of Chicago. His adoptive father was a poor Russian immigrant who told his son he would never amount to anything, according to a biography on Ellison by Mike Wilson.

After his adoptive mother died, Ellison dropped out of college and headed to California, jumping from one job to another.

He has said that he "had all the disadvantages required for success," and founded his database company, Oracle, in 1977.

An admirer of Japanese culture, his favorite saying is reportedly from Genghis Khan, who said, "It's not sufficient I succeed. Everyone else must fail."