Warren Buffett recently released his 53rd annual letter to shareholders recently–a financial analysis that investors and financial experts are always eagerly devour for its wit and wisdom. The Oracle of Omaha commands attention, but it wasn’t always that way. Early in his career, Buffett was “terrified” of public speaking and took specific steps to overcome his fear.

You can make the argument that if Buffett had not overcome his stage fright, he may never have become a billionaire. Buffett would later tell a class of business students that effective public-speaking raises a person’s value by 50% instantly. At the age of 21, his renewed confidence in front of people gave him the courage to advise investors who were older than him and gave him the courage to propose to his wife, Susie, which Buffett says was the most important decision of his life.

Here’s how he managed to gain confidence in public speaking.

1. Take small steps to improve.

 “In my office, you will not see the degree that I got from the University of Nebraska. You will not see the master’s degree I got from Columbia University. But you will see the award certificate I got from the Dale Carnegie Course,” Buffett said in the HBO documentary, Becoming Warren Buffett.

Buffett didn’t overcome his stage fright in an instant. You may not know this: He actually signed up for a public-speaking course run and dropped out before it started–because he was afraid of public speaking!

He completed the Dale Carnegie course on his second try. The certificate he proudly displays in his office reads: “Warren E. Buffett has successful completed the Dale Carnegie Course in effective speaking, leadership training, and the art of winning friends and influencing people. January 13, 1952.”

Buffett followed up the course by teaching an investment class at a local college. He realized that he needed to shore up his confidence by just doing it–over and over in front of small groups.

Trained professionals rely on “exposure therapy” as one of the most effective techniques to treat anxiety. Buffett was performing a form of exposure therapy on himself–putting himself in more frequent anxiety-providing situations, like speaking in front of a small group of students or teaching a class. Eventually, familiarity with a stressful situation alleviated the fear.

 2. Reinterpret nerves as something positive.

 After you put yourself in a situation that produces anxiety–like speaking in front of a group–a critical step is to reinterpret or “re-frame” your nerves as a positive response to the opportunity.

In her book Choke, psychology professor Sian Beilock says delivering a speech, negotiating a business deal or hitting a golf shot can trigger the same negative thoughts. If you tell yourself that you can’t do it, your body will produce stress hormones that elevate heart rate and make your palms sweat.

There is a mental hack that helps. “If you can manage to interpret your body’s response to the situation as positive, as a call to action, you are likely to thrive,” writes Beilock. In other words, stop worrying and start enjoying the process.

No matter how many times you’ve spoken in front of groups, we all get butterflies. It’s natural because our innate desire to be accepted by a group is hardwired in our brain over millions of years. When I begin to feel those butterflies, I tell myself it’s a sign my energy and confidence are high, and that I’m ready to inspire the audience. It always works to put a smile on my face. Don’t eliminate your butterflies; let them fly in formation.

Buffett reinterpreted his fear. Instead of looking at it public speaking as something negative, he re-framed it into an opportunity to gain a competitive advantage over his young peers in the industry. “I couldn’t do it. I knew that if I didn’t cure it then, I’d never cure it,” Buffett recalled in the HBO documentary.

3. Practice like it’s the real thing.

Beilock says that practicing is a key to overcoming the fear of public speaking. The secret is practicing the right way–by putting yourself under a little stress. “Practicing under the types of pressures you will face on the big testing day is one of the best ways to combat choking,” she writes.

Buffett may not have have understood the psychology behind his actions at the time, but by standing up in front of a class day after day, he was building his confidence for bigger and bigger venues. A little stress in front of a small class would lead to a lot less stress when he spoke to larger audiences.

When I work with executives who are uncomfortable about speaking in public, I recommend adding “a little stress” to their practice presentations. You can add stress by delivering the presentation out loud in front of a small group of staff or peers. Simply reviewing the slides quietly in your head isn’t the same as speaking in front of people.

Long before he became a billionaire, Buffett recognized that public speaking skills would be critical to his success as a financial advisor. He took specific steps to build his confidence; steps that anyone can–and should take–to conquer the most common fear of all.