Billionaires Like Warren Buffett, Jeff Bezos and Mark Cuban Live by Ancient Stoic Philosophy Staying humble and knowing that we don't know everything are big success factors.

It all started around 304 BC when Zeno, a wealthy merchant and founder of Stoicism, sailed from the Mediterranean  port of Piraeus, known for its notoriously stormy weather. Zeno  was shipwrecked and lost everything, but when he finally arrived in Athens, he famously discovered philosophy.

The rest of course, is history – or shall we call it, philosophy?

Today the philosophy of Stoicism still lives on and is used by the rich, wealthy and powerful, though having wealth doesn't mean that we need to drive expensive cars or wear expensive clothes. As investor and entrepreneur Tim Ferriss once put it, Stoic philosophy is "a simple and immensely practical set of rules for better results with less effort."

The CEO of Berkshire Hathaway, Warren Buffett is known for his frugality. According to CNBC, he never pays more than $3.17 for breakfast and still lives in the house he bought for $31,500 in 1958 (approximately $260,000 today).

Ikea founder Ingvar Kamprad is the eighth-richest person in the world with a personal worth an estimated $58.7 billion, according to Bloomberg. For two decades, Kamprad drove a 1993 Volvo 240 GL. He only gave it up when his daughter persuaded him that driving it was dangerous.

The founder and CEO of Facebook, Mark Zuckerberg, drives a black Acura TSX, a car valued around $30,000. He says he prefers the choice because it's "safe, comfortable and not ostentatious."

Why would Buffett, Kamprad and Zuckerberg spend very little money? Instead of focusing on externals, these billionaires focus on the things that really matter. Let's dive in to find out what truly matters to these billionaires.

Related: 5 Epic Leaders Who Studied Stoicism -- and Why You Should Too

Live below your means.

Lebron James has a net worth of around $440 million dollars but instead of paying for expensive subscriptions, he uses free WIFI and free music streaming services like Pandora. NBA player Trey Burke of the New York Knicks earns a million dollars a year but has allotted himself a $5,000 a month budget to live on.

Like Buffett who has been content in the same house for 60 years, James and Burke have cultivated spending habits below their means so that they can focus on what really matters to them. It just so happens that they are wealthy. Having clarity about what they value in the world gives them total freedom from their possessions. If they lost it all  they would still have what matters to them most -- their happiness.

Many business moguls and billionaires strategically use this strategy.

Amazon founder, Jeff Bezos built a culture around frugality and constraint. Why? "I think frugality drives innovation, just like other constraints do," he said. "One of the only ways to get out of a tight box is to invent your way out."

Billionaire Shark Tank investor Mark Cuban knows about the power of frugality. "The more you stress over bills, the more difficult it is to focus on your goals. The cheaper you can live, the greater your options."

Marcus Aurelius famously sold all of this palace furnishings to pay down the debt weighing down him and his people. Remember, the more we want and desire, the less we can focus on what truly matters to us  -- joy, freedom and living a good life.

Related: These 7 Lessons From the Ancient Stoics Are Relevant for Entrepreneurs Today

Failure is the stepping stone to success.

Billionaires like Mark Cuban and Warren Buffett don't claim to know everything, which is why they are voracious readers and learners. Staying humble and knowing that we don't know everything are big success factors.

Epictetus (as well as modern college teachers) was annoyed by students who wanted to learn, yet thought they knew everything. You see this with many entrepreneurs today. As Socrates said, "All I know is that I know nothing".

The billionaire investor George Soros says that "Once we realize that imperfect understanding is the human condition, there is no shame in being wrong, only in failing to correct our mistakes." And Einstein famously said "The definition of insanity is doing the same thing over and over again and expecting different results." Doing the same thing over and over again is easy. It doesn't take a new thought or any more effort, which is why most people do it.

But you can do more and be better. Learn from your failure.

"If you are defeated once and tell yourself you will overcome, but carry on as before, know in the end you'll be so ill and weakened that eventually you won't even notice your mistake and will begin to rationalize your behavior."

Epictetus, "Discourses," 2.18.31

Related: 5 Truths of Ancient Wisdom That Will Make You a Better Entrepreneur

Controlling your limited time.

Buffett instinctively knows that "you've gotta keep control of your time, and you can't unless you say no. You can't let people set your agenda in life. The difference between successful people and really successful people is that really successful people say no to almost everything." When you say no you're protecting your time and energy so you can focus on the important things in life.

Seneca says that while we might be good at protecting our physical property, we are far too lax about enforcing our mental boundaries. "Property can be regained --  there is quite a bit of it out there and some of it still untouched by man. But time? Time is our most irreplaceable asset, and we cannot buy more of it."

Today, when people try to steal your time and attention, remind yourself of what Ingvar Kamprad, the founder of IKEA, once observed: "You can do so much in 10 minutes' time. Ten minutes, once gone, are gone for good. Divide your life into 10-minute units and sacrifice as few of them as possible to meaningless activity."

In the end, actively applying these three seemingly simple principles to our lives can transform us to new levels of health, wealth and happiness. The stoics call it Eudaimonia -- The Good Life.