Forbes just published its annual list of the richest people on the planet. Warren Buffett ranks third with a net worth of $50 billion.

It was hard to ignore that when I traveled to Buffett's office in Omaha last month to interview him for a television documentary I'm currently producing.

I was told I'd have 15 minutes with Buffett. Hours were spent preparing and refining questions for the greatest investor of all time. I flew out to Nebraska the night before the scheduled interview and arrived at his office the following morning in time to watch the camera crew set up.

I was struck by the simplicity of the Berkshire Hathaway headquarters. There was no expensive art. No custom furniture. No spacious suites. It was a remarkable testament to frugality and a stunning contrast to the many corporate headquarters I've visited previously.

I also couldn't help noticing all the framed pictures of him that decorated the walls. In almost every one he was wearing a simple business suit and laughing. That's also exactly what he was doing when he came through the door at the appointed time of our interview. Smiling and joking, he treated me and the rest of my team as if we were his friends. Then he sat down in the chair and we were rolling.

The next 15 minutes were among the most electric ones of my career. I asked him business-related questions. But it's the stuff he said about life that convinced me that the Oracle of Omaha's most valuable wisdom may be in his perspective on happiness and relationships.

For instance, he told me that one of the secrets to his success and longevity (he's 80 years old and works as hard as ever) is that "it hasn't been a question of going to work; it's been a question of tap-dancing to work." His love for his job, he said, has never worn off.

I felt the same way as I was making my way across the country to meet him. The privilege of writing — whether for books, magazines, blogs or a TV documentary — has made my life rich in experiences, like the one I was having with Buffett. Journalism will not land me on a Forbes list. But Buffett's point is that money isn't the point. Loving one's profession is worth its weight in gold.

Another thing that struck me about Buffett is the way he treats the people around him. David Neeleman, the founder of JetBlue Airways and the current CEO of Azul Airlines in Brazil, once told me it's easy to be nice to people that you need things from. The question, he said, is how do you treat the person who can do absolutely nothing for you?

Neeleman's question gets to the subjects of gratitude and humility. Buffett seems to have these down. In preparation for my interview with him, I'd been given access to a stack of personal letters that Warren had written to one particular CEO of a company that Berkshire Hathaway acquired back in the 1990s. The letters were remarkably poignant and complimentary. The fact is that Warren didn't need to write them. Moreover, you'd think a guy as busy as he is wouldn't have time to write letters of thanks. So I asked:

"Why do you write letters like that and is that something you do all the time, or just with this one particular CEO?"

He responded: "Quite a few of them. I appreciate our managers and if you appreciate people you ought to tell them. You don't know where you're going to be tomorrow. You don't know where they're going to be tomorrow. It applies outside of business. I've had all kinds of people do all kinds of things for me — grade teachers in the past — I've had a lot of good luck with people. I believe in telling them so. I'd like it if people told me. It's nice to get those letters."

It's true. We don't know where we'll be tomorrow. Nor do we know where those we care about will be in a week or two. A couple years ago I started writing letters — lots of them — to people that have influenced my life over the years. Few things are more gratifying than penning the words THANK YOU to a grade school teacher, a childhood friend, an old neighbor or someone who took a chance on you when no one else would.

I wouldn't be where I am today if it wasn't for a guy named Art Taylor, who gave me an internship opportunity in Boston in 1992. He took a personal interest in me. That opportunity led to my career as a writer. One of the best things I've ever written was a letter to him saying thank you for giving me a chance.

The last thing Buffett told me was my favorite. It had to do with confidence.

"My father always told me that basically I could do anything," Buffett said. "He never tried to shove me in any given direction. Getting unconditional love and getting approval develops confidence."

If I were a preacher, I'd say amen to that. Unconditional love is the hardest kind … especially when it comes to the people we claim to love the most, like spouses, children and parents. Encouragement and praise go so much further than criticism and blame.

At the end of our interview, I asked Warren if we could take a few pictures together. He cupped his hand and pretended to whisper in my ear. Then he told the photographer: "I'm giving him a stock tip."

Jeff Benedict is a best-selling author and a columnist for SI.com. He can be reached at jeff@jeffbenedict.com.