Success doesn't have to be measured by how much money you make or how many companies you build.
In fact, if you ask some of the world's wealthiest individuals what success means to them, they won't mention money, investments or even numbers at all.
Here's how Bill Gates, Mark Cuban and five other self-made billionaires define success.
Richard Branson, founder of the Virgin Group
Estimated net worth: $5 billion
"Too many people measure how successful they are by how much money they make or the people that they associate with," Branson writes on LinkedIn. "In my opinion, true success should be measured by how happy you are."
"It's a common misconception that money is every entrepreneur's metric for success," he continues. "It's not, and nor should it be."