Simply put, school isn't for everyone. Although there tends to be a stigma attached to being a high-school or college dropout, a number of well-known and highly successful men began their careers by taking a calculated risk and dropping out of school. Here are six such individuals.

Note: All amounts are in U.S. dollars.

 

1. Simon Cowell
Dropped out of: A London boarding school in 1975 at age 16.

Cowell was such a poor student that the school held him back a year, which landed him in his younger brother's grade. His family was well-connected — his family's neighbor was the head of MGM studios in London, and Stanley Kubrick, who would one day buy the Cowell family home, offered him some work on The Shining — but when Cowell went down to the EMI studio in Hertfordshire and saw so many people standing in line for work on the film, he decided it wasn't for him. He wanted to make his own money, so he applied for a job in the mail room at EMI and worked his way up to record producer.

His accomplishments: These days, Cowell is best known for his role as the acerbic judge on American Idol, for which his salary is estimated at over $30 million. He owns a record label, has successfully promoted various bands and artists — including the international operatic group Il Divo — and is the highly successful creator/producer of such TV shows as Pop Idol and American Inventor.

By graduation time: By the time Cowell would have graduated from boarding school, he'd already been working as a clerk in the mail room at EMI for 18 months and was soon to become a producer. It wasn't until the mid-'80s that Cowell started his own record label, Fanfare.

 

2. William H. (Bill) Gates III
Dropped out of: Harvard University in 1975 at age 20.

He dropped out in large part due to the urging of his childhood friend Paul Allen. Gates and Allen convinced MITS (Micro Instrumentation and Telemetry Systems) — the makers of the first microcomputer, Altair — that they had written a version of the programming language BASIC that would work well on the Altair. It was a lie — they hadn't written a single line of code — but they went to work and finished it in eight weeks.

His accomplishments: Bill Gates is the co-founder, chairman and chief software architect of Microsoft Corporation, the worldwide leader in personal and business computer software. The company currently employs more than 64,000 people across 85 countries.

Although he has recently taken a back seat with regard to Microsoft's day-to-day operations, Gates remains highly influential in the corporation. He is the richest person in the world according to Forbes' 2006 list and is widely considered to be the world's most giving humanitarian, as he has donated more than half his fortune to charities.

By graduation time: By the time Gates would have graduated from Harvard, he and Allen had formed Microsoft, based largely on their version of BASIC.

 

3. John Mackey
Dropped out of: Three different Texas colleges in the mid-1970s.

Mackey, a strict vegetarian at the time, soon started his own natural foods store, where he sold food dropped off by local farmers.

His accomplishments: Today, the visionary Mackey — sometimes called the Bill Gates of organic food — is Chairman and CEO of Whole Foods Market, a $3.8 billion Fortune 500 company and the world's largest natural foods retail chain. While other supermarket chains post losses, Whole Foods has prospered, thanks in large part to Mackey's highly stylized approach to business, which includes his personal beliefs in vegetarianism (he is now technically a vegan), the value of all-natural health foods, and working with animal rights groups to adopt more humane treatment standards for animals.

Mackey is also highly regarded for taking a lower salary than other CEOs might and for making certain that all Whole Foods workers are involved in profit sharing.

By graduation time: By the time he would have graduated, Mackey and his then-girlfriend had borrowed money from friends and family to start a vegetarian food company, Safer Way, out of a garage in Austin. Within two years, he had founded Whole Foods Market.

 

4. Ron Popeil
Dropped out of: A Florida high school in 1951 at age 16.

Popeil himself admits his childhood was so terrible that he's actively blocked much of it out. His parents divorced when he was 3 and he was sent off to a New York boarding school soon afterward. Unable to tolerate it, he went to live with his grandparents in Florida, but by 16, he could no longer tolerate that situation either. He dropped out of school and went to live with his father, Samuel Popeil, a Chicago-area inventor, who sold his products to companies such as Sears and Woolworth.

His accomplishments: Popeil, the highly recognizable father of the infomercial and inventor of such products as the Veg-O-Matic and the Food Dehydrator, created Ronco in 1964. He began running advertisements for his various products on television, which was still a relatively new medium. All told, Popeil's inventions have generated over $1 billion in retail sales. He recently sold Ronco for $55 million, but he remains the company's spokesman.

By graduation time: By the time Popeil would have graduated from high school, he was working for his father. Initially, Popeil would set up a table in stores and try to convince both customers and store owners to buy his father's products. Soon, Samuel was selling his inventions to Ron — at wholesale, meaning that Samuel was making a profit — who would then sell them to stores.

 

5. Russell Simmons
Dropped out of: City College of New York in 1977 at age 20.

Russell dropped out after hearing a singer named Eddie Cheeba working a New York City club by calling out rhymes. Saying he had an epiphany, Simmons decided to pursue this emerging music scene and began promoting local music groups and producing their albums.

His accomplishments: Hip-hop and rap pioneer Simmons is the creator of Rush Communications, a huge conglomerate that includes two record labels (Def Jam Records and Russell Simmons Music Group), a management company, a clothier (Phat Farm), a movie production house, television shows, a magazine, and an advertising agency. Although he recently sold his stake in Def Jam and Phat Farm, Simmons remains a highly influential media figure, and has a net worth estimated at over $500 million.

By graduation time: By the time Simmons would have graduated, he was busy promoting local music groups that included Kurtis Blow, Run DMC and Public Enemy. In 1984, when in his late 20s, he and Rick Rubin founded Def Jam, signing such acts as LL Cool J and the Beastie Boys. The following year, they signed a production deal with CBS for $600,000 and were eventually responsible for getting Run DMC on MTV as the channel's first rap act.

 

6. Sir Alan Michael Sugar
Dropped out of: Brooke House School in London in 1963 at age 16.

He went briefly into the civil service as a statistician, but having come from a relatively low-income family, Sugar soon turned to the business of buying and selling — cigarette lighters, intercoms, car stereos, and antennae — in order to make his way in the world.

His accomplishments: Today, Sugar's net worth is estimated at approximately $1.5 billion, thanks in part to various successful business ventures, including Amstrad, his electronics and computer business, and Amsair, a company providing charter jet services. He is currently the star of BBC's The Apprentice, assuming the role Donald Trump has on the American version of the television show, and was at one time a part owner of Tottenham Hotspur Football Club.

By graduation time: By the time Sugar would have graduated from high school, he was still selling fruits and vegetables out the back of a van paid for with his then-life savings of $185. His hard-won business acumen served him well, however; within five years, he founded Amstrad, which would eventually make him a multi-millionaire.

Where there's a will there's a wayIf there is a lesson to be learned from the lives and careers of successful dropouts, it isn't that dropping out of school is always a good idea. Rather, it's that dedication and hard work — whether applied at school or at the proverbial school of hard knocks — will always prove rewarding if you believe in your dream and work hard to achieve it.