It’s well known that legendary investor Warren Buffett answers investor questions for hours every year at Berkshire Hathaway Inc’s (NYSE: BRK-A) (NYSE: BRK-B) annual meeting of shareholders. But most don’t know that such wouldn’t have been possible in Buffett’s early days.

If it weren’t for a $100 college course he took when he was 20 years old, the “Oracle of Omaha” might have shorted his own success.

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What To Know: Buffett had an extreme fear of public speaking up until the age of 20, according to a report from CNBC.

“Just the thought of it made me physically ill. I would literally throw up,” Buffett told CNBC contributor and “Getting There” author Gillian Zoe Segal.

In his early college days, Buffett would select certain classes to avoid having to present in front of his classmates. Furthermore, he designed his schedule so he wouldn’t have to be in front of crowds.

He told Segal that he could barely even introduce himself whenever he found himself in a situation that required him to speak in front of others.

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Buffett set out to change that when he saw an ad for a Dale Carnegie public speaking course at Columbia’s Business School. He signed up and even wrote a check to cover the costs, but shortly after, he reneged on his intentions.

“I just couldn't do it. I was that terrified,” the Berkshire CEO said.

Not long after Buffett graduated, he came across the exact same ad in the paper and set out to sign himself up again, with one key difference in his approach.

“This time, I handed the instructor $100 in cash. I knew if I gave him the cash I'd show up,” Buffett said.

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He did show up, and he discovered that about 30 other people had the same problem he did, he said: “We all had trouble saying our own names.”

By the time he finished the 12-week course, he was ready to put his skills to the test. He applied for a teaching position at the University of Omaha right away, knowing that if he didn’t keep at it, he would risk giving up the progress he had made in the public speaking class.