Consequently, our extensive collection of businesses currently consists of a few enterprises that have truly extraordinary economics, many that enjoy very good economic characteristics, and a large group that are marginal," Buffett wrote.
But in the spirit of humility, let's take a look at three of Buffett's worst decisions, and what investors can learn from them.
"What I had assessed as a durable competitive advantage vanished within a few years," Buffett wrote in his 2007 letter to shareholders.
Compounding the mistake, Buffett paid $443 million for the company in Berkshire stock rather than cash.
"As a financial disaster, this one deserves a spot in the Guinness Book of World Records," Buffett wrote in his 2014 shareholder letter.