Billionaire buddies Bill Gates and Warren Buffett have noticed something that might seem obvious. As the Oracle of Omaha succinctly puts it:

"In the world of business, the people who are most successful are those who are doing what they love."

He elaborates, even going so far as to say that passion is more important than intelligence: "Being successful at almost anything means having a passion for it. If you see somebody with even reasonable intelligence and a terrific passion for what they do, things are gonna happen."

If that sounds like the advice your parents gave you -- especially you millennials -- when you were in high school or college, that's probably because it's identical. In this day and age, the idea of "following your passion" has become ubiquitous. The question is, are you doing it?

Do it for the love, not the money 

Following your passion sounds like easy advice for billionaires to give, right? They have the money to spend their time however they please. The thing is, before Buffett and Gates began leap frogging each other for the position of richest individual in the world, they were still following their passions.

According to Buffett, "I've always worked in a job I love. I loved it just as much when it was a big deal when I made a thousand bucks."

Gates told a group of Harvard students that "The thing that you're likely to be world-class at is whatever you obsessed over from age 12 to 18. In my case, it was writing software." If you think Gates was making a fortune coding software as a 12-year-old, think again.

Instead, he was just smitten: "I was 13 years old when I fell in love with programming. My school had just become one of the first in the country to get a computer terminal. The machine was huge and slow, and it didn't even have a screen -- but I was hooked."

Be prepared to sacrifice

If the combined wisdom of Gates and Buffett isn't enough to impress you, you might find it interesting that the late Steve Jobs adhered to the same philosophy.

As he explained in his commencement speech to Stanford's Class of 2005, it wasn't always easy. Telling the story of how he dropped out from Reeds College because of the price tag, he admits that "It was pretty scary at the time, but looking back it was one of the best decisions I ever made. The minute I dropped out I could stop taking the required classes that didn't interest me, and begin dropping in on the ones that looked interesting."

Jobs went on to found Apple, but things didn't work out so well on the first go around and he was ousted from his own company.

Without his passion, he would have hit rock bottom -- and he might not have bounced. In his own words, "I'm convinced that the only thing that kept me going was that I loved what I did. You've got to find what you love... Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work."

Don't be discouraged if finding what you love is harder than you thought. Instead, Jobs urges you to trust that it will be worth the wait. "If you haven't found it yet, keep looking. Don't settle. As with all matters of the heart, you'll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So keep looking until you find it."

Simply put, don't settle.