When so many others were running scared last autumn, Mr. Buffett invested billions in Goldman Sachs  and got a far better deal than Washington. He then staked billions more on General Electric. While taxpayers never bailed out Mr. Buffett, they did bail out some of his stock picks. Goldman, American Express, Bank of America, Wells Fargo, U.S. Bancorp  all of them got public bailouts that ultimately benefited private shareholders like Mr. Buffett.

If Mr. Buffett picked well  and, so far, it looks as if he did  his payoff could be enormous. But now, only a year after the crisis struck, he seems to be worrying that the broader stock market might falter again. After boldly buying when so many were selling assets, his conglomerate, Berkshire Hathaway, is pulling back, buying fewer stocks while investing in corporate and government debt. And Mr. Buffett is warning that the economy, though on the mend, remains deeply troubled.

“We are not out of problems yet,” Mr. Buffett said last week in an interview, in which he reflected on the lessons of the last 12 months. “We have got to get the sputtering economy back so it is functioning as it should be.”

Still, Mr. Buffett hardly sounded shellshocked in the wake of what he once called the financial equivalent of Pearl Harbor. (An estimated net worth of $37 billion would be a balm to anyone’s psyche.)

“It has been an incredibly interesting period in the last year and a half. Just the drama,” Mr. Buffett said. “Watching the movie has been fun, and occasionally participating has been fun too, though not in what it has done to people’s lives.”