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."
Tilman Fertitta, CEO of Landry's
Estimated net worth: $2.8 billion
"Success to me is anybody who does something better than somebody else," Fertitta tells CNBC.
The skill or craft is irrelevant, he says: "I don't care what business it is. I have the greatest respect in the world for that guy that can take an engine apart of a car and put it back together, or the house painter that can paint a perfect line, or the cameraman who can shoot the best shot.
"We're all talented in our own ways — just some of us make more money than others. That's all."
Mark Cuban, entrepreneur, "Shark Tank" investor and owner of the Dallas Mavericks
Estimated net worth: $3.4 billion
"To me, the definition of success is waking up in the morning with a smile on your face, knowing it's going to be a great day," Cuban tells Steiner Sports. "I mean, I was happy and felt like I was successful when I was poor, living six guys in a three-bedroom apartment and sleeping on the floor. I was going to work hard to get somewhere, but I was having fun."
Oprah Winfrey, entrepreneur, TV host, actress
Estimated net worth: $3 billion
"The key is not to worry about being successful but to instead work toward being significant — and the success will naturally follow," Winfrey writes on her website.
Warren Buffett, chairman and CEO of Berkshire Hathaway
Estimated net worth: $78.6 billion
In Alice Schroeder's biography of Buffett, "The Snowball, " she writes about a time when Buffett was addressing students at Georgia Tech. Someone asked him about his greatest success and he responded, "Basically, when you get to my age, you'll really measure your success in life by how many of the people you want to have love you actually do love you.
"I know people who have a lot of money, and they get testimonial dinners and they get hospital wings named after them," he continued. "But the truth is that nobody in the world loves them. If you get to my age in life and nobody thinks well of you, I don't care how big your bank account is, your life is a disaster.
"That's the ultimate test of how you have lived your life. The trouble with love is that you can't buy it ... The only way to get love is to be lovable," said Buffett. "The more you give love away, the more you get."
Bill Gates, co-founder of Microsoft
Estimated net worth: $86.7 billion
When Gates is asked to define success in a Reddit Ask Me Anything session, he cites his friend: "Warren Buffett has always said the measure is whether the people close to you are happy and love you."
In addition to making sure the loved ones in his life are happy, he believes there's a second critical component of success: Making the world a better place. Gates writes: "It is also nice to feel like you made a difference — inventing something or raising kids or helping people in need."
John Paul DeJoria, co-founder of Paul Mitchell hair products and Patron Tequila
Estimated net worth: $3 billion
"Success isn't how much money you have," DeJoria tells Business Insider. "Success is not what your position is. Success is how well do you do what you do when nobody else is looking."