In the arts, a master class is a group lesson with an acknowledged expert—a chance for students to hear from an undisputed master and to improve their work by being exposed to the best.

This last weekend, I joined almost 40,000 other “students” to attend the master class for investors that is the Berkshire Hathaway annual meeting.

I’m a member of the Berkshire Hathaway board, and this weekend is one of the most enjoyable “duties” of my year. As per usual, Warren Buffett and his longtime business partner Charlie Munger sat on stage in Omaha, Nebraska, for over five hours answering questions from reporters, financial analysts, and Berkshire shareholders. Many shareholders had travelled great distances to be part of the weekend.

Like all those other students of value investing, I sat there amazed at the breadth, depth, and humility on display. Warren and Charlie talked about executive compensation in the United States; how to look at the intrinsic value of companies; the harsh winter just past and its effects on the railroad business; trends in the boxed candy market; the value of brands; and the potential impact of self-driving cars on the auto insurance industry—just to name a few.

Warren also talked about the invaluable role Charlie has played for him in leading Berkshire. I thought about the remarkable partnerships I’ve had over my career with Paul Allen and with Steve Ballmer. And now, with Melinda as we work together on the goals of our foundation.

I’ve heard Warren talk about many of those topics before, but each time I hear him, I learn something, and I come away with deeper respect and admiration for my friend.