Investing guru Warren Buffett offers some heartfelt advice: If you truly want to be rich in your lifetime, invest in yourself.

"Ultimately, there's one investment that supersedes all others: Invest in yourself," Buffett says in a recent interview with Forbes.

"Nobody can take away what you've got in yourself, and everybody has potential they haven't used yet,” CNBC quoted the chairman of Berkshire Hathaway Inc. as saying.

The billionaire has transformed Berkshire since 1965 from a failing textile company into a conglomerate with more than 90 businesses in such sectors as insurance, railroads, energy and retail, and well over $100 billion of stocks.

Buffett tells Forbes that you can increase your potential "by simply being able to communicate better" and "enhancing your talents."

Buffett is college-educated, but when he got started, he took a speaking course through Dale Carnegie, Forbes.com explained.

"I was terrified of public speaking when I was young. I couldn't do it," Buffett says.

"You can't believe what I was like if I had to give a talk," Buffett recalls in the biography "The Snowball: Warren Buffett and the Business of Life." "I would throw up."

Buffett also has unlimited confidence in America despite any uncertainty about how the United States will cope with growing tumult.

Buffett’s optimism for the country’s prospects over the long term, even 100 years into the future.

“Whenever I hear people talk pessimistically about this country, I think they’re out of their mind,” Buffett said last month in New York at an event celebrating the 100th anniversary of Forbes magazine, and is on the cover of an issue featuring 100 of the world’s greatest living “business minds.”

Buffett said he expects the Dow Jones Industrial Average to be “over 1 million” in 100 years, up from Tuesday’s close of 22,370.80. He said that’s not unreasonable, given how the index was roughly 81 a century ago.

But he knows he won’t be around to see it happen, Reuters explained.

“When I hear talking about making it to 100, I get excited,” he said. “I‘m 87.”

Nonetheless, he said long-term investing remains the way to go.

He noted that since Forbes created its first list of the 400 richest Americans in 1982 -- Buffett was worth just $250 million then -- some 1,500 different people have been included.

All with one thing in common.

“You don’t see any short sellers,” he said, referring to people who bet stock prices will fall.

“It has been 241 years since Thomas Jefferson wrote the Declaration of Independence,” he said. “Being short America has been a loser’s game. I predict to you it will continue to be a loser’s game.”

(Newsmax wires services contributed to this report).