Approach everything with integrity

During their lunch, Buffet explained how he and his longtime business partner Charlie Munger approach the truth, honesty and integrity. "He and Mr. Munger use an internal yardstick," Pabrai told CNBC.

Buffett gave the men an unconventional method to determine their integrity, asking them: "Would you rather be the greatest lover in the world yet be known as the worst, or would you rather be the worst lover and be known as the greatest?"

"And he said, 'If you know how to answer that correctly, then you have the right internal yardstick,'" recalled Pabrai.