#5 It took Larry Ellison a bit longer than the others to find his calling

Lawrence Joseph "Larry" Ellison is an American business magnate, co-founder and chief executive of Oracle Corporation, one of the world's leading enterprise software companies.

At 20, Ellison was a bright but inattentive student. He left the University of Illinois at Urbana-Champaign after his second year, after not taking his final exams because his adoptive mother had just died. After spending a summer in Northern California, where he lived with his friend Chuck Weiss, Ellison attended the University of Chicago for one term, where he first encountered computer design. In 1964, aged 20, he moved to northern California.

During the 1970s, after a brief stint at Amdahl Corporation, Ellison worked for Ampex Corporation. One of his projects was a database for the CIA, which he named "Oracle". Ellison was inspired by the paper written by Edgar F. Codd on relational database systems called "A Relational Model of Data for Large Shared Data Banks". In 1977, he founded Software Development Laboratories (SDL).

Read Also: 20 Countries With Biggest Internet Users and 10 Most Money-Filled Tech Markets Of 2013