Thomas Edison, inventor

The prolific inventor holds 1,093 patents in the United States, including the motion picture camera, yet was considered an "addled" student and left school after only a few months.

Walt Disney, founder, Walt Disney Productions

The legendary animator dropped out of high school at 16 to join the army, but was rejected for being underage. He instead joined the Red Cross, drove an ambulance in France for a year, then returned to the United States to pursue his career in cartoons and animation.

Dave Thomas, founder, Wendy's

Thomas got his first restaurant job in Knoxville, Tennessee, at the age of 12, and within a few years he had dropped out of high school to work full-time at the Hobby House Restaurant in Fort Wayne, Indiana.

In his early 60s, Thomas returned to school and earned his GED. His classmates named the fast-food magnate "Most Likely to Succeed."

Ringo Starr, drummer, The Beatles

Richard Starkey suffered from a string of illnesses including tuberculosis as a boy, which caused him to fall well behind his peers in school. Throughout his teens, he developed an interest in the drums, and by the time he was 20 he was performing as Ringo Starr. Soon enough, he was behind the kit for The Beatles and on his way to becoming one of the most famous drummers of all time.

Peter Jennings, journalist

Toronto-born journalist Peter Jennings had his first show on Canadian radio by the age of nine, and dropped out of high school at 17. He went on to become one of the most recognized foreign correspondents in the world and anchored ABC News' World News Tonight from 1983 until his death in 2005.

Simon Cowell, record executive / TV personality

The divisive judge on talent shows like American Idol got his first job at a record label at 16 when he went to work in the mail room at EMI. He was held back in school and eventually dropped out.

Jay-Z, rapper / entrepreneur

Born Shawn Carter in a notorious Brooklyn housing project, Jay-Z attended Westinghouse Career and Technical Education High School but never graduated. In his late 20s, his rap career flourished and he went on to become one of the most financially-successful musicians in North America, thanks to a number of business ventures including the Rocawear clothing brand.

Quentin Tarantino, filmmaker

Eccentric, award-winning director, screenwriter and actor Quentin Tarantino left high school during his freshman year to study acting, and released his first film, the acclaimed Reservoir Dogs, before his 30th birthday.