I found all kinds of wisdom in this interview with economist Peter Bernstein. It was originally published in 2004 and the updated online a couple of years ago. A lot of the wisdom sounds familiar, as most general wisdom does, but occasionally Bernstein offers a twist. For instance, I like this passage:
I make no excuses or apologies for changing my mind. The world around me changes, for one thing, but also I am continuously learning. I have never finished my education and probably never will.... I'm always telling myself, "I must sit down and explain why I said this, and why I was wrong."
People often speak the virtue of changing our minds, but Bernstein goes further: he feels a need to explain both the reason he thought what he did and the reason he was wrong. That sort of post-mortem can be immensely helpful to the rest of us as we try to learn, and the humility of explaining the error keeps us all better grounded.
I found quotable passages on almost every page. One quoted Leibniz, which I paraphrased as:
von Leibniz told Bernoulli that nature works in patterns, but "only for the most part". The other part -- the unpredictable part -- tends to be where the action is.
Poking around the fringes of a model that is pretty good or a pattern of thought that only occasionally fails us often brings surprising opportunities for advancement.
Many of Bernstein's ideas were framed specifically as about investing, of course, such as:
The riskiest moment is when you're right. That's when you're in the most trouble, because you tend to overstay the good decisions.
Diversification is not only a survival strategy but also an aggressive strategy, because the next windfall might come from a surprising place.
These ideas are powerful outside the financial world, too, though. Investing too much importance in a productive research area can be risky because it becomes easy to stay there too long after the world starts to move away. Diversifying our programming language skills and toolsets might look like a conservative strategy that limits rapid advance in a research niche right now, but it also equips us to adapt more quickly when the next big idea happens somewhere we don't expect.
Anyway, the interview is a good long-but-quick read. There's plenty more to consider, in particular his application of Pascal's wager to general decision making. Give it a read if it sounds interesting.