Look at market fluctuations as your friend rather than your enemy; profit from folly rather than participate in it.

Focus on your customers and lead your people as though their lives depend on your success.

The most common cause of low prices is pessimism - some times pervasive, some times specific to a company or industry. We want to do business in such an environment, not because we like pessimism but because we like the prices it produces. It's optimism that is the enemy of the rational buyer.

Businesses always have opportunities to improve service, product lines, manufacturing techniques, and the like, and obviously these opportunities should be seized. But a business that constantly encounters major change also encounters many chances for major error

At Berkshire, I both initiate and monitor every derivatives contract on our books ... If Berkshire ever gets in trouble, it will be my fault. It will not be because of the misjudgments made by a risk committee or chief risk officer.

I mean you know at midnight everything is going to turn to pumpkins and mice; right? But if the evening goes along, I mean, you know, the guys look better all the time, the music sounds better, it's more and more fun, you think why the hell should I leave at quarter of 12. I'll leave at two minutes to 12. But the trouble is, there are no clocks on the wall. And everybody thinks they're going to leave at two minutes to 12.

If AIG had tried to unwind their derivatives books. I don't know. It would have hit every institution in the world.