Charlie Munger died on Nov. 28 at age 99. These reflections on his life and career, which he wrote for CNBC Make It, are among his final writings.

My children and grandchildren might not think exactly the way I do, but I hope they can observe my life as an example of how to be successful in their careers and relationships — just as I did with the generations before me. 

When I was very young, my father practiced law. One of his best friends, Grant McFayden, Omaha's Pioneer Ford dealer, was a client. He was a brilliant and self-made man, with enormous charm and integrity.

In contrast, my father had another client who was pompous, unfair and difficult. One day, I asked my dad, "Why do you do so much work for Mr. X, this overreaching blowhard, instead of working more for wonderful men like Grant?" 

"Grant treats his employees right, his customers right, and his problems right," my father said. "He doesn't have enough remunerative law business to keep you in Coca-Cola. But Mr. X is a walking minefield of wonderful legal business."

This conversation taught me that sometimes, you may have to sell your services to an unreasonable blowhard, especially if that's what you must do to feed your family. But you want to run your own life like Grant McFayden. 

That was a great lesson that my father shared in a very clever way. Instead of just pounding it in, he told it to me in a way that required a slight mental reach. Since I had to reach for it, I've never forgotten it. And I've used his teaching method with my own children and grandchildren.

Here, two of my kids Charles and Wendy share key lessons they've learned from me over the years. My hope is that they'll hold onto all of these until their 100th birthdays. 

Always return a borrowed car with a full tank of gas.

"On the last day of a family ski vacation in Sun Valley, when I was about 15, my dad and I were driving back in the snow when he took a 10-minute detour to gas up the red Jeep we were driving.

He was pressed for time to have our family catch the plane home, so I was surprised to notice as he pulled into the station that the tank was still half full. I asked my dad why we had stopped when we had plenty of gas, and he admonished me, "Charlie, when you borrow a man's car, you always return it with a full tank of gas."

My freshman year at Stanford, an acquaintance lent me his car. The favor was more because friends we had in common twisted his arm, than because he knew me all that well. The tank was half full, and the Audi Fox was red, which reminded me of that Jeep.

So I topped up the tank before I brought the car back. He noticed. We've had many good times since, and he was a groomsman in my wedding.

My dad never skipped a point of fairness and consideration. His example taught me how to get a good friend — and how to keep one."

—Charles T. Munger, Jr.

Never try to hide your mistakes.

"My dad often used the family dinner table as a forum to try to educate his children. One of his favorite educational tools was the 'Morality Tale,' in which someone faced an ethical problem and had to choose the correct path.

I remember a story he told us about a financial officer at one of his companies who made a mistake that resulted in the loss of hundreds of thousands of dollars to the business. Once he realized his mistake, he went directly to the president of the company and told him about it.

The president said, 'This was a terrible mistake, and we don't want you ever to make another one like it. But people make mistakes, and we can forgive that. You did the right thing, which was to admit your mistake. If you had tried to hide it or cover it up for even a short time, you would be out of this company. As it is, we'd like you to stay.'

I always remember this story every time I hear of yet another government official who chose to cover up their mistake, instead of being honest and leading with integrity."

—Wendy Munger

Charlie Munger was Vice Chairman of Berkshire Hathaway, and Warren Buffett's closest business partner and right-hand man. As a legendary and pragmatic investor and active philanthropist, Munger was a Harvard Law graduate and was known for his wide-ranging wisdom across a multitude of disciplines — including psychology, economics, biology, history and physics. Munger served as a director of Costco Wholesale Corporation and as chairman of the Daily Journal Corporation.

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