Chances are, you've been advised to "follow your passion" or "do what you love" at one point in your life.
Billionaire entrepreneur Mark Cuban says to ignore that conventional career advice. In fact, "'follow your passion' is easily the worst advice you could ever give or get," the "Shark Tank" star wrote on his blog in 2012.
Your passions "aren't worth a nickel," he continues. "Think about all those passions that you considered making a career out of or building a company around. How many were/are there? … Why were you not able to make a career or business out of any of those passions?
"Or, if you have been able to have some success, what was the key to the success? Was it the passion or the effort you put into your job or company?"
Rather than following your passion, follow your effort, says Cuban: "Look at where you apply your time. ... You may or may not realize it yet, but how you use or don't use your time is going to be the best indication of where your future is going to take you."
For Cuban, that meant pursuing something in the technology industry.
"I was never into technology in college. I took one computer class and cheated at it," he recalls.
"But when I got one of my first jobs out of school using technology, it was like, 'Wait, I love this.' I've taught myself the program, I could go seven hours, eight hours without taking a break thinking it was 10 minutes because I was concentrating so hard and so excited and really loved it.
"And that's when I realized that I can be really, really good at technology."
Cuban went on to start a computer consulting service, MicroSolutions, which he sold to CompuServe in 1990 for $6 million.
Five years later, Cuban and friend Todd Wagner created an online streaming audio service called Broadcast.com so they could listen to Hoosiers basketball games in Texas. Yahoo acquired the business in 1999 for $5.9 billion in stock.
The self-made billionaire argues that when you spend hours working hard at something, you get good at it; and when you get good at something, you tend to enjoy it more.
"When you enjoy doing something, there is a very good chance you will become passionate or more passionate about it," the billionaire writes. "When you are good at something, passionate and work even harder to excel and be the best at it, good things happen."
Like this story? Like CNBC Make It on Facebook!
Don't miss: Why one CEO tells young people that 'do what you love' is bad advice
