Warren Buffett recently released the 2017 Berkshire Hathaway shareholder letter. The letter is part performance review and part market wisdom, often with a dose of humor.

So what can ordinary investors learn from the 87 year-old Oracle of Omaha? In this year’s letter, Buffett cautioned against assuming too much debt — specifically, he discussed why Berkshire Hathaway makes investments with equity, not borrowed money.

He noted that while debt can improve returns, he sleeps easier at night this way. “It is insane to risk what you have ... in order to obtain what you don’t need.”

He also reminded us not to act so that we feel like we’re doing something. Instead: “Stick with big, ‘easy’ decisions and eschew activity.”

Here are a few more quotes, all of which are smart lessons for investors, large and small.

“It is not necessary to do extraordinary things to get extraordinary results.”

In 2013, Buffett advised the trustees of his estate to “put 10 percent of the cash in short-term government bonds and 90 percent in a very low-cost S&P 500 index fund. ... I believe the trust’s long-term results from this policy will be superior to those attained by most investors ... who employ high-fee managers.”

Buffett has long held that investors are better off with low-cost index funds than paying higher fees to managers, especially hedge fund managers. At the end of last year, Buffett claimed victory over Ted Seides in “The Million-Dollar Bet.” In that 2007 wager, Buffett challenged any active manager to beat the S&P 500 index with a portfolio of hedge funds. The only taker was Seides, who was the founder of asset manager Protégé Partners LLC, where he served as president and co-chief investment officer.

Buffett didn’t just win — he killed it. The average annual gain for the index fund over 10 years was 8.5 percent. The five funds of hedge funds selected by asset manager Protégé Partners reported average annual gains between 0.3 percent and 6.5 percent.

As Buffett aptly noted, “When trillions of dollars are managed by Wall Streeters charging high fees, it will usually be the managers who reap outsized profits, not the clients.”

“Over the long term, the stock market news will be good.”

In October 2008, amid the worst financial crisis in a generation, Buffett wrote an op-ed urging investors to maintain the faith.

He underscored an important point: “I can’t predict the short-term movements of the stock market. I haven’t the faintest idea as to whether stocks will be higher or lower a month — or a year — from now. What is likely, however, is that the market will move higher, perhaps substantially so, well before either sentiment or the economy turns up.”

Remember that sentiment when you are tempted to time the market’s next move.

“Successful investing takes time, discipline and patience. No matter how great the talent or effort, some things just take time: You can’t produce a baby in one month by getting nine women pregnant.”

There are some who question why Berkshire is sitting atop $100 billion in short-term government bonds right now. I think this quote provides more insight.

Buffett is the consummate disciplined investor. Although it has been more than two years since his last big purchase, he adheres to strict guidelines. Perhaps the most important of which is that the opportunity must be available at “a sensible purchase price.” Otherwise, he is content to be patient.

Jill Schlesinger, CFP, is a CBS News business analyst. She welcomes comments and questions at askjill@jillonmoney.com.