[throwawayarnty]

The lack of enthusiasm to learn new stuff is also due to opportunity costs and “exploration vs exploitation“ dynamics.

You spend time and effort when you are younger (eg 15) to develop skills that allow you to be productive and valuable.

Learning entirely orthogonal skills when you’re older no longer pays off after a certain point because the opportunity cost of not using your existing skills to produce becomes too large.

To make an extreme analogy, there is no point in Warren Buffet to learn to program at his stage of his career (or even 30 years ago). Any time spent not reading financial reports is such a huge opportunity cost that he really has no reason to learn any other skill.

Another extreme example is Lang Lang the pianist has no reason to pick up the violin. He has absolutely nothing to gain by learning new musical instruments.

Science is a special career where learning new things is important for longevity. A productive science career involves breaking new ground, picking up the low hanging fruit before your competitors do, then move on to break new ground once your old field becomes saturated. Learning new things is strategic, where you try to leverage existing expertise to break ground in new fields.

[munificent]

I agree with this 100%. I also think this is the primary driver of the old observation that people get more conservative as they age. (I'm using "conservative" in the more basic sense of "generally opposed to change" here and not in the current US political sense.)

One way to define of "experience" is "optimize for solving problems in the current environment". As you accrue experience, the best way to provide value to others is in an unchanging world that lets you leverage what you already know. When the world changes, some of your experience gets invalidated, making you less useful. So there's a natural incentive to prefer the status quo as you age, not out of any intrinsic heartlessness or selfishness, but just because you are most useful to yourself and others in a familiar world.

The young, however, don't feel this same pressure. They have relatively little experience—i.e. they aren't particularly good at getting things done in the current environment—and they do learn quickly. So they are incentivized to want change and to explore novel environments since those environments are no worse for them than the current one. Or, in other words, every environment is equally novel when you're young, so why not try a new one that puts you on more even footing with the older folks?

[rossdavidh]

Your analysis of the cost-benefits is mostly sound, but I think in the case of programming it breaks down. People's instincts are to think that now that they have become expert, they shouldn't need to be a neophyte again. This works in most fields, but then you see programmers at age 35 realizing that the pool of jobs for their skillset is shrinking, and their labor market leverage is shrinking with it. Yes, there are those last few COBOL gigs, but they only become lucrative after 90%+ of the COBOL programmers have given up and got out.

This is likely always true, but in most fields the skill remains in demand for centuries; wainwright may not pay like it used to (or maybe it does, I don't know) but the decline in demand is slow enough that nobody has to bail out, as long as youngsters aren't continuing to plow into that field it's fine. In programming, the hotness of 10 years ago may already be at its peak, and if you're not willing to move on when you're in your 30's to learn something new, you have sentenced yourself to decades of working in a shrinking job market, which is kind of soul-crushing. Nothing to make your current job intolerable like thinking there's nowhere else you can go.

So, while Lang Lang may not choose to pick up the violin, it is probably fine, because the pianoforte is going to be a good skillset for the rest of his life. The harpsichord players who refused to move on to piano or organ may not have had a crisis in mid-career, because the transition from harpsichord to piano was slow enough to happen over generations. Programming tech changes faster than that (for better or worse).