Virgin Group founder .
Since dropping out of school at age 16 to start his first business, Branson has overseen hundreds of companies. Along the way, he's accumulated a fortune of approximately $5 billion.
The entrepreneur says in the business world is simple: "It doesn't matter who you are, entrepreneurship boils down to and being resourceful enough to turn it into a reality.
"Questions like 'where did you go to school?' rarely have a place in entrepreneurship — it's all about bringing ideas, with the power to change things, to life."
Facebook's Mark Zuckerberg agrees.
"The best companies that get built are things that are trying to drive some kind of social change, even if it's just local in one place," he says in an interview with Y Combinator.
People often start a company simply to start a company, or because they want to make a lot of money or have a bunch of people working for them. "That feels really backwards to me," Zuckerberg says. "Start with the problem that you're trying to solve in the world."
Don't identify any random problem, the Facebook co-founder emphasizes. Pick something you truly feel passionate about. "For anyone who's had the experience of actually building a company, you know that you go through some really hard things along the way, and I think part of what gets you through that is believing in what you're doing."
"And that," he says, "is how the best companies end up getting made."