But when he's not reading or working, chances are the billionaire is playing bridge.
"I play a lot ... at least four sessions a week, about two hours a session," Buffett told Thomas Heath of the Washington Post in a recent interview. That's a minimum of eight hours a week.
Buffett, who is, at 87 years old, as sharp as ever, likes the challenges that the game of bridge presents.
"You can play a hand every six or seven minutes every day for the rest of your life, and you will never see the same hand," he tells Heath. "It's a game you can enjoy when you are in your 90s, and you are seeing a different intellectual challenge every seven minutes."
Buffett's longtime friend Bill Gates is also a fan of the game. During a 1995 couples trip to China organized by Gates and his wife Melinda, "we were playing bridge while everyone was looking at the scenery," Buffett tells Heath. "We played on the bus while balancing cards on our knees."
It's not too surprising that these successful leaders spend so much time playing an intellectually stimulating game. It keeps them thinking.
Author Steve Siebold, who has studied more than 1,000 wealthy people, found that they would rather be educated than entertained. "The rich like entertainment but love to learn, and they spend their entire lives soaking up information and using it to get richer every day," he writes in his book, "How Rich People Think."
The card game may also keep Buffett, Gates and Munger sharp for longer. As research published in the Journal of American Academy of Neurology finds, those who engage in mentally stimulating activities experience slower memory decline than those who do not.
And bridge may be the most mentally stimulating activity, according to Buffett: "It's the best exercise there is for the brain."
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