"I'll tell you something even better than one stock," Buffett said. "The best investment--by far--is developing yourself" For years, Buffett hosted business school students who made a pilgrimage to his office in Omaha to meet with him. The students were often surprised when Buffett showed off his most prized diploma--a framed certificate from a public-speaking course. "I have one diploma hanging in my office," Buffett would tell them. "It's from a Dale Carnegie course, which cost me a hundred bucks back in 1951. It's incalculable how much value I got from that hundred dollars."