Who better than Warren Buffett to teach us a valuable lesson on success? The Oracle of Omaha offers up a profound bit of truth in this advice related to our work:

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

Think about it. Does that thought ever run through your mind in your daily corporate grind? For most of us, we take for granted our cushy paycheck, health benefits, and job security, even though we may despise our jobs and wish we were doing something else -- something we actually loved.

Buffett may as well be a life coach in billionaire disguise. Listen to how he urges us to consider a better future, when he says, "You need to really think about what will make you proud when you are old and look back on your life. That is the right direction to take."

Apple CEO Tim Cook agrees

Buffett has highly esteemed company. Tim Cook was once asked by a reporter what advice he had for personal success. Cook's response, like Buffett's, was almost anticlimatic, yet full of simple truth and wisdom:

"Do what you love, and put your whole heart into it, and then just have fun."

Conversely, after receiving an honorary degree from the University of Glasgow last year, he told students in a speech, "You have to find the intersection of doing something you're passionate about and at the same time something that is in the service of other people. I would argue that, if you don't find that intersection, you're not going to be very happy in life."

Doing what we love is a major contributor to our happiness as humans. And, more important, knowing what you love should be a top priority. If you don't know what it is you love, then finding out what it is should be your first step.

Science says doing what you love = success and happiness

Interestingly enough, conventional wisdom leads us into believing that building our wealth is what will increase our happiness. One popular Princeton study, in fact, found that happiness rises as income rises, up until you hit the magic income of $75,000 a year -- at which point happiness doesn't improve as you earn more.

But what if the opposite is true? What if, in reality, happiness (doing what you love) is what leads to greater wealth?

Several recent studies support this idea, including a research paper published in the Proceedings of the National Academy of Sciences that found that adolescents and young adults who report higher life satisfaction earn significantly higher levels of income later in life.

There are several reasons why happy people who love their work are able to earn more money, including:

1. Happy people are more optimistic.

Happy employees are more open to opportunity and new experiences; they are willing to accept challenges and take risks, which are predictors of greater earning opportunity.

2. Happy people are healthier and more productive.

According to research, happy employees stay home 15 fewer days a year, on average, than unhappy workers -- and live up to 10 years longer. On the flip side, poor health has an adverse effect on productivity and the work hours of an individual, leading to a decline in income, writes University of Western Sydney economics professor Satya Paul in "Reversing the Causality -- Does Happiness Reduce Income Inequality?" Being productive at work has obvious benefits because it puts you in better position for a promotion and salary increase.

3. Happy people are enthusiastic about growing.

Happy people earn more because they learn more. They're are always looking to improve themselves and invest in their future. This is a sure way to set you on the path toward success.

Closing thoughts

Circling back to Buffett's prophetic quote, if happier people who love what they do earn greater incomes, a multitude of possibilities exist for companies to change the business environment, helping to create happier employees. Think about it: People-centered leaders who are aware of how happiness generates success could hire happier people. Happier employees would be more productive, thus increasing the company's profitability and, in the long run, increasing the employees' income for a better life and future.