A recurring trap in investing is that the more committed we become to a company or thesis, the harder it can be to question its key assumptions without unconsciously defending the conclusion.

Creative destruction is hard. We say "oh, I'm going to start doing [New Activity]" but we don't cede an old one. Charlie said, per Whitney Tilson, "Any year that passes in which you don't destroy one of your best loved ideas is a wasted year", in 2004 at the Wesco annual meeting. mungerarchive.com - Learning any year passes

I think that is a very important, and very gnarly notion. I moved on from Caterpillar this year - it is an AI stock now? The valuation was rather lofty. It did its job; it was a quarter century long holding and I'm retired. Eli Lilly, same thing a year or two ago...the valuations simply were too lofty for what were good but mature businesses.

This is hard with people - Warren has discarded a few he was enamored of, usually quietly, like David Sokol, but usually we hang on to them, hoping they'll improve, wishing for the old days. I tossed an old High School era friend, who foundationally has become a surly old bigot now - I realized I wouldn't associate with them if they were newly introduced to me. But it is hard.

I've used this notion with bosses, when I was still working. New ones come in, all enthused, and we're going to do this-and-that, and I ask what are we going to *stop* doing. They tend to get a bit derailed when I ask, and don't seem to like the question, but you can only squeeze so much from the workforce.

Greg will likely make some discards. Some may wait until Warren is gone, out of regard, if they're more minor. Some may come as (for us aficionados) surprises like if Greg slaughtered the Coke sacred cow.