Every year, Warren Buffett writes a Thanksgiving letter to the shareholders of Berkshire Hathaway, the extraordinary company he has presided over from Omaha, Nebraska, since 1965. Investors have long admired his wisdom about companies and markets, of course, but we were struck by the reflections and the common sense contained in this year’s letter—much of which had nothing to do with Berkshire Hathaway or the stock market. We asked Buffett if we could publish an excerpt for this week’s Ancient Wisdom, and to our delight, he said yes. Enjoy.

As Thanksgiving approaches, I’m grateful and surprised by my luck in being alive at 95. When I was young, this outcome did not look like a good bet. Early on, I nearly died.

It was 1938, and Omaha hospitals were then thought of by its citizens as either Catholic or Protestant, a classification that seemed natural at the time.

Our family doctor, Harley Hotz, was a friendly Catholic who made house calls toting a black bag. Dr. Hotz called me Skipper and never charged much for his visits. When I experienced a bad bellyache, Dr. Hotz came by and, after probing a bit, told me I would be okay in the morning.

He then went home, had dinner, and played a little bridge. He couldn’t get my somewhat peculiar symptoms out of his mind, however, so later that night he dispatched me to St. Catherine’s Hospital for an emergency appendectomy. During the next three weeks, I felt like I was in a nunnery, and began enjoying my new “podium.” I liked to talk—yes, even then—and the nuns embraced me.

To top things off, Miss Madsen, my third-grade teacher, told my 30 classmates to each write me a letter. I probably threw away the letters from the boys but read and reread those from the girls; hospitalization had its rewards...