Warren Buffett, CEO of Berkshire Hathaway, wasn’t always the confident speaker known today. Public speaking once made him “physically ill.” Determined to overcome this fear, Buffett took a $100 course at Dale Carnegie Training after graduating from Columbia Business School in 1951, Buffett shared this insight with author Gillian Zoe Segal during an interview for her 2015 book, “Getting There: A Book of Mentors. What Happened: Buffett credits this course as having a significant impact on his success, stating that even modest improvements in communication skills can greatly enhance future earnin…