What is one of the best or most worthwhile investments you have ever made — of money, time, or energy?

So I find that teaching and the students keep life going, and I would never accept any position in which somebody has invented a happy solution for me where I don’t have to teach.  Never.

We've just passed a milestone: Twenty years ago, on January 3, 1972, Blue Chip Stamps (then an affiliate of Berkshire and later merged into it) bought control of See's Candy Shops, a West Coast manufacturer and retailer of boxed-chocolates. The nominal price that the sellers were asking - calculated on the 100% ownership we ultimately attained - was $40 million. But the company had $10 million of excess cash, and therefore the true offering price was $30 million. Charlie and I, not yet fully appreciative of the value of an economic franchise, looked at the company's mere $7 million of tangible net worth and said $25 million was as high as we would go (and we meant it). Fortunately, the sellers accepted our offer. The sales of trading stamps by Blue Chip thereafter declined from $102.5 million in 1972 to $1.2 million in 1991. But See's candy sales in the same period increased from $29 million to $196 million. Moreover, profits at See's grew even faster than sales, from $4.2 million pre-tax in 1972 to $42.4 million last year.

Amos and I shared the wonder of together owning a goose that could lay golden eggs – a joint mind that was better than our separate minds. … Some of the greatest joys of our collaboration-and probably much of its success – came from our ability to elaborate each other's nascent thoughts: if I expressed a half-formed idea, I knew that Amos would be there to understand it, probably more clearly than I did, and that if it had merit he would see it. Like most people, I am somewhat cautious about exposing tentative thoughts to others – I must first make sure that they are not idiotic. In the best years of the collaboration, this caution was completely absent.

Tree planting became a natural choice to address some of the initial basic needs identified by women. Also, tree planting is simple, attainable and guarantees quick, successful results within a reasonable amount time. This sustains interest and commitment.

Sherry offered me a list of research options: the one project that intrigued me the most consisted of finding out the environmental fate of certain very inert industrial chemicals – the chlorofluorocarbons (CFCs) – which had been accumulating in the atmosphere and which at that time were thought to have no significant effects on the environment. This project offered me the opportunity to learn a new field – atmospheric chemistry – about which I knew very little; trying to solve a challenging problem appeared to be an excellent way to plunge into a new research area.

But from day one, I really wanted to build the kind of company my father never got a chance to work for. A company that honors and respects the dignity of work and the dignity of all men and all women. And that is why we became the first company in all of America to provide comprehensive health insurance 30 years ahead of the affordable care act, as well as ownership in the form of stock options for all of our employees, including part-time people because it is my firm belief that success in business and in life is best when it's shared.

Well, it is of course a step-by-step process that started back in the 80s. I was struggling to retrieve a little bit of DNA from things that were just a few … starting with just dried tissues that, you know, that were just a few months old, going back in time and struggling with the technological issues with that over a decade. And then it became possible to retrieve DNA from things like the mammoths or cave bears that lived at a similar time as the Neanderthals. And then I was very lucky to get a job in Germany, where of course Neanderthals is a big presence in our, in the imagination of people, so it was then very, an obvious next step, in a way, to try to do that.