They're the world's most successful self-made billionaire entrepreneurs. But as children they were known as:

  • a "nerdy guy"
  • an "eccentric misfit"
  • a "lippy, headstrong kid"
  • a "boy wonder"
  • a "regular kid"
  • a boy who was motivated by "a slap on the face"

Their identities are below, and they're worth exploring because most parents will do just about anything to increase the odds their kids will be successful--and that can mean figuring out what some of the world's most successful people's childhoods were like.

They grew up in all kinds of conditions, but they became the most iconic names of their generations. They began their journeys like this:

1. Mark Zuckerberg: "a nerdy guy."

I've written quite a bit about Zuckerberg, given that his father has talked freely about the child-raising philosophy he and Zuckerberg's mother shared: model self-employment and entrepreneurship, shield your kids from financial concerns, encourage them to find their interests, express pride, and set limits.

While at prep school in the early 2000s, Zuckerberg wrote a program that used artificial intelligence to predict users' music preferences, and was tempted to skip college. But he went to Harvard, fortunately, for during his brief time there he both started Facebook and met his future wife, Priscilla Chan--while waiting in line for a bathroom.

"He was this nerdy guy who was just a little bit out there," Chan told The New Yorker in 2010.

2. Jeff Bezos: an "eccentric misfit."

Bezos grew up with his mother and stepfather (who adopted him) and spent summers working on his grandparents' farm. He was his high school's valedictorian and a National Merit Scholar before enrolling at Princeton, where he was one of about 20 students in the electrical engineering and computer science (EECS) program.

A Princeton classmate recalled on Quora, "You have to remember, he wasn't famous back then, and there were brilliant people everywhere. ... [W]e EECS geeks ... were a quiet, overwhelmingly male group of eccentric misfits."

3. Larry Ellison: a "lippy, headstrong kid."

The 73-year-old founder of Oracle Corporation was raised by his great-aunt and great-uncle "in a cramped walkup apartment in the middle-class South Side neighborhood," according to an interview he gave 20 years ago. "By all accounts he was a lippy, headstrong kid who had little use for his teachers or his adoptive father, with whom he fought often as a teenager."

He had "a string of half-forgotten jobs" before landing at a couple of tech companies, and ultimately starting Oracle in 1977 with $2,000--including $1,200 of his own money. There were some stressful years, but by the mid-1980s, Oracle was one of the most-successful Silicon Valley startups.

4. Bill Gates: "a boy wonder."

Gates grew up comfortably in Seattle, the son of a prominent lawyer and a banker, and had his first exposure to computers in the late 1960s while attending prep school, at a time when very few young people had access. This led ultimately to Gates's first paying job, at age 16, working for a now-defunct company called TRW that was computerizing the power grid in the Pacific Northwest.

"I was sort of infamous as a boy wonder of a certain type of programming," Gates later recalled. "It was a seminal experience for me, because TRW had brought its very best programmers to program there... I would write code and these super-smart guys would look it over and tell me, 'Hey, this isn't very good, this isn't very good,' so my whole programming skill during the year I was there went a whole notch up."

5. Mike Bloomberg: "a regular kid."

Bloomberg was born into a middle-class family outside Boston. Neither a great student nor a great athlete, he was nevertheless driven. He reached the rank of Eagle Scout "before he was old enough to qualify," according to one account. His sister described him as "just a regular kid."

After attending Johns Hopkins University, Bloomberg went on to Harvard Business School and headed to Wall Street, eventually becoming a general partner at Salomon Brothers. Ultimately laid off, he parlayed $10 million in equity into launching the business information technology company that would later bear his name.

6. Amancio Ortega: a boy who suffered "a slap on the face."

The billionaire on this list least known to Americans, both because he's European and because he's by highly reclusive, Ortega is the co-founder of European retailer Zara, and according to a biography, he grew up very poor in postwar Spain. His drive to succeed came when he was about 14, after his mother was turned away from a shop while trying to buy food, because the family no longer had credit.

"The consequence of that slap on the face he suffered when still he was a very young boy has been the creation of one of the most important Spanish enterprises... with a global presence in most of the world," biographer Covadonga O'Shea said.