In truth, the better question may be: How could they not?

From Jeff Bezos to Elon Musk and Bill Gates, it is difficult to find one hugely successful businessperson today who doesn't reap the benefits of something called stoic philosophy. Hoping to join these leaders in their mindsets and accompanying success? Learning what, exactly, stoicism is and what it teaches is a great place to start.

Stoicism's central teachings remind us how unpredictable the world can be, and the philosophy gives us the tools we need to be steadfast and in control of our emotions and reflexive senses. It asks us to reflect on ourselves and what matters to us most. Billionaire Warren Buffett, in alignment with the principles of stoic philosophy, has taken these ideals to heart. In the words of Marcus Aurelius:

"What's left to be prized? This, I think--to limit our action or inaction to only what's in keeping with the needs of our own preparation... by having some self-respect for your own mind and prizing it, you will please yourself and be in better harmony with your fellow human beings, and more in tune with the gods--praising everything they have set in order and allotted you." -- Marcus Aurelius, Meditations

Buffett still lives in the Omaha home he originally purchased 59 years ago for a mere $31,500--despite the fact that his current net worth is in the neighborhood of $77 billion. He may be one of the richest people on the planet, however, he is a big fan of McDonald's, home of the Dollar Menu. Every morning on the drive to work, Buffett stops at the local McDonald's where he orders a Coke and a simple breakfast item. Total price? Never more than $3.17. Says Buffett,

"I tell my wife, as I shave in the morning, I say, 'Either $2.61, $2.95 or $3.17.' And she puts that amount in the little cup by me here [in the car]. When I'm not feeling quite so prosperous, I might go with the $2.61, which is two sausage patties, and then I put them together and pour myself a Coke. $3.17 is a bacon, egg and cheese biscuit, but the market's down this morning, so I'll pass up the $3.17 and go with the $2.95."

Why doesn't Buffett spend extravagantly when he has all the financial means to do so?

Buffett lives below his means because he has prioritized what truly matters most to him, and these priorities do not include luxuries--expensive homes, expensive cars, expensive food. In cultivating low-cost interests and passions, he is able to further build his wealth and maintain financial freedom.

Now is as good a time as any to incorporate a little stoicism in your own life or workplace. Figure out what matters the most to you, and where you can adjust your behavior and spending habits. In doing so, you will get on the same track with today's greatest business successes.