I had the great privilege to conduct a very short interview with David Einhorn.

For anyone unfamiliar with him, Einhorn is the co-founder of Greenlight Capital, a long-short value hedge fund, which he started with $900k in 1996. The fund now has more than $8 billion AUM (assets under management).

Greenlight has been closed to new investors for several years. Since 1996, Einhorn’s fund has generated greater than 30 percent gross returns per annum.

In 2008, David Einhorn authored "Fooling Some of the People All of the Time," a book about Allied Capital, a medium-size financial company that was involved in various types of fraud.

He shorted the company in 2002, and the company collapsed and was on the verge of bankruptcy in 2008, until they were bought out by Ares Capital in 2009. The book was written before the company collapsed, and in 2010 Einhorn came out with an updated version of his book commenting on the collapse of Allied.

Here was my question to David and his response:

Jacob Wolinsky: Most people write a book when the story is over. The first edition of your book came out while Allied capital was still trading at $20 a share. How did you have the confidence to publish a book when it was possible things would not work out as you expected, were you thinking this might be the next Dow 36,000?

David Einhorn: I didn’t know how or when the story would end. I did know that our research was correct, so I remained optimistic. I believed it was necessary to publish the book even without an ending because the broader story was important.

Investors can learn many important lessons from Einhorn’s comment.

However, the most important thing I believe investors should take from Einhorn, is the necessity of patience in investing.

The stock market can be quite a wild ride for investors. Many individual and professional investors do not have the temperament or patience to sit on an investment that is losing money or not going anywhere.

This is especially true when all your friends are bragging about how much money they made in their portfolio, and bragging about their stock picks. However, this attitude usually shifts when the market is getting crushed and the macro picture looks very bad.

In early 2009, if you talked to someone about buying stocks at a cocktail party they would probably recommend a shrink. Now, you will hear your neighbor who might not know what the SEC is, bragging about his great stock picks.

The intelligent and most successful investors ignore all the noise.

Einhorn was publically attacked by the media and Allied Capital throughout the ordeal. He not only was able to stay focused, but he even wrote the book while the company was trading at a high price.

While investors should reassess their investments if there is a large change in price or the fundamentals of the business collapse; Einhorn’s message always has value, be patient in your attitude, and if you have done real extensive research on a company, never change your opinion based on your emotions and what others think.