First, I want to point out that everything I’m saying here is fairly obvious. I just felt like writing it down. And once it’s down, why not share it..?
Almost everything we know, we learned at some point. The concepts of ‘compound interest’ or of ‘anchoring bias’ might seem pretty straightforward, but a younger version of you heard of these for the first time at some point and — if the concepts stuck and were integrated — had its view of the world changed, at least a little.
Some people happen to be really talented at doing certain things and really good at teaching others about these things.
People like Warren Buffett, Richard Feynman, Charlie Munger, Daniel Kahneman & Amos Tversky, etc. These are pretty revered names, but there are also many other mentors and teachers operating at levels below the superstars. They might not be quite as well-known or have reputations quite as bullet-proof, but they are still very good at what they do (and even those at the top of the pyramid will always attract their share of detractors and/or contrarians who dislike them in large part because they are too popular).
I’ve noticed an interesting phenomenon in my fields of interest, and I think it probably happens elsewhere too. The general way it goes is something like this: People who have been around the field for a while become increasingly disenchanted with their old mentors and talk about how they used to have good insights but now mostly recycle the same things, their best stuff was their earlier stuff, etc. It often leads to a kind of retroactive downgrade of the mentor’s value, probably through a kind of “curse of knowledge” where, once you know something, it’s hard to put yourself back in the shoes of someone who doesn’t know and see how valuable being taught these things was, and how non-obvious they used to be to you.
I’ve seen it a lot with Warren Buffett, because he’s such an unavoidable name in the investing world. People talk about his letters getting boring and redundant, always going for the same anecdotes and explanations that he used before during interviews, etc.
I think what happens can be illustrated with a graph:
The top line is some mentor. They’re already at the top of their game, or close to it, by the time you start learning from them. If they weren’t, they probably wouldn’t be on your radar.
You start near the bottom, but you are in the steep part of the your learning curve, so you progress fast. In the early days, there’s lots of ‘low hanging-fruit’ insights and concepts to be picked from the mentor(s). Basically, your mind is being updated rapidly as you download knowledge from various sources.
At some point, the learning curve starts to level off, and while you might keep improving for the rest of your life, the rate of change is much lower. This isn’t a value judgement since it can be just as hard, or harder, to go the last 10% of the way as it is to go the first 90%, since by that point the insights almost by definition have to be harder to uncover and sources of progress have to be more difficult to tap.
But it’s that last little bit that makes a difference if you’re in a field where you’re competing against other people who probably also went through a similar progression. If everyone can fairly easily and rapidly get through the first 90%, what will separate the wheat from the chaff will be mostly found in that last, harder-to-get, 10%.
So if we look at you and your mentor during the period relevant to your own progress, they start way ahead of you, but you rapidly catch up a good fraction of the way. They might still keep improving, but the rate at which they keep getting better usually won’t be nearly as fast as the rate that you’re improving at during the early part of the curve. So the difference between the two lines becomes much smaller, and even if the remaining delta makes all the difference in performance (ie. even if many investors are 80% of the way to Buffett, it’s the other 20% that makes Buffett stand out), it still means that you can’t possibly get as much out of them as you could at first. The low-hanging fruits have all been picked.
This is why you get “mentor fatigue”. Buffett’s more recent letters will seem worse to someone who has read 40 of them before, because Buffett can’t possibly generate entirely new insights as fast as he’s writing letters. After all, he’s also in the harder-going, less steep part of his own learning curve.
But I suspect that if Buffett’s recent letters and interviews had been the first ones that you had ever been exposed to, you’d probably have been much more impressed by them and the insights that seemed redundant to an experienced Buffett-follower would cause important learning and mind-updating to someone getting started.
Even if there was a way to objectively show that the more recent output from a mentor is worse than their earlier stuff (and often I agree it clearly is), I don’t think the delta is as large as it might seem to someone who is closer to the mentor in skill than to someone who’s closer to the bottom.
