No wise pilot, no matter how great his talent and experience, fails to use his checklist.

You must value the business in order to value the stock.

You've got to have models in your head and you've got to array you experience - both vicarious and direct - onto this latticework of mental models.

There's no way that you can live an adequate life without making many mistakes.

Proper accounting is like engineering. You need a margin of safety. Thank God we don't design bridges and airplanes the way we do accounting.

After nearly making a terrible mistake not buying See's, we've made this mistake many times. We are apparently slow learners. These opportunity costs don't show up on financial statements, but have cost us many billions.

A lot of people think if you just had more process and more compliance -- checks and doublechecks and so forth -- you could create a better result in the world. Well, Berkshire has had practically no process. We had hardly any internal auditing until they forced it on us. We just try to operate in a seamless web of deserved trust and be careful whom we trust.