Steve Jobs apparently believed in finding your passion. As Jobs once said, "You've got to find what you love. The only way to do great work is to love what you do. If you haven't found it yet, keep looking.

Mark Cuban disagrees. As Cuban said: "One of the great lies of life is 'follow your passions.' 'Follow your passion' is easily the worst advice you could ever give, or get."

Who is right? As you'll see, both--especially where starting and building a business is concerned.

You have to have a lot of passion for what you do, and the reason is it's so hard that if you don't, any rational person would give up.

You have to do it (build a company) over a sustained period of time. If you don't really love it, you're going to give up.

For Cuban, passion comes later

A lot of people talk about passion, but that's really not what you need to focus on.

When you look at where you put in your time, where you put in your effort, that tends to be the things that you are good at. And if you put in enough time, you tend to get really good at it.

If you put in enough time, and you get really good, I will give you a little secret: Nobody quits anything they are good at, because it is fun to be good. It is fun to be one of the best. But in order to be one of the best, you have to put in effort.

So don't follow your passions. Follow your effort.

Actually though, their approaches are more similar than not.

Before starting Apple, Jobs was passionate about things like Eastern mysticism, calligraphy, and dance. Not technology.

So when Jobs teamed with Woz to sell kit computer circuit boards to hobbyists, the "business" was a side hustle. When local businessman Paul Terrell told Jobs he would buy 50 fully assembled computers for $500 each, Jobs was simply jumping at the chance to make even better money. 

Jobs spotted an opportunity, pursued that opportunity and, in the process, found his (business) life's work.

That's also what Cuban does. Take artificial intelligence and machine learning. According to Cuban, "The world's first trillionaires are going to come from somebody who masters A.I. and all its derivatives, and applies it in ways we never thought of."

That's why he completed Amazon's machine learning tutorials. That's why he spent time building his own neural networks. That's why, at one point, he kept the book Machine Learning for Dummies in his bathroom.

"The more I understand A.I., the more I get excited about it," Cuban said

Neither Jobs nor Cuban waited until they discovered their passions.

Instead, they developed them.

Which is how, according to a 2014 study published in the Academy of Management Journal, the same process often works for entrepreneurs. 

While most people, and most theoretical frameworks, assume that entrepreneurial passion drives entrepreneurial effort, research shows the reverse is also true: Entrepreneurial passion increases with effort.

The more work entrepreneurs put into their startups, the more enthusiastic they get about their businesses. As they gain momentum, gain skill, and enjoy small successes--even if those "successes" only involve ticking off items on their seemingly endless to-do lists--their passion grows. 

So yes, passion can spark effort. But effort can in turn spark passion--passion that then often leads to even greater effort. And greater passion. And greater effort. 

And one day you wake up and realize you're doing what you love.

Even though it didn't start out that way.

If you want to start a business but haven't found your "passion," that's OK. Find an opportunity. Find a gap. Find a way to fill a need or solve a problem, one that fits a skill you have or are willing to put in the effort to develop. 

Then work hard to seize that opportunity.

While others are waiting, you will be doing. Learning. Growing. Gaining the skills, experience, and expertise required to build a successful business.

Because passion doesn't have to be discovered.

Passion can also be developed.

Science, as well as Jobs and Cuban, says so.