There was a lot I learned from my estranged discussion partner EB. One point of emphasis he made in terms of personal development was the importance of muscle memory, of extreme repetition until the conscious act becomes unconscious. One example he liked was the book "Zen in the Art of Archery" where the student rehearses the same motions again and again and again over months, just the most basic part of correct form, like drawing the string without releasing it, in painstaking detail. Examples of that kind of learning in life are hard to come by.
When my Aunt Susan visited last week and she and Melissa and I picked up my family's traditional pastime of Dr. Mario - or specifically as I tried to describe techniques and things to watch to Melissa who is new to the game and playing with a giant handicap - it hit me that Dr. Mario has some of that. I have distant, decade-old memories of what the game used to feel like: epic struggles, and I even have shadow-memories (or more exactly, meta-memories) of specific in-game board situations, like say where I was feverishly trying to deal with two situations on either side of a block tower, or had to build way up to some junk above when there was no room to slide pieces over it as they fell. Now everything is very business-like, and while I can generally give voice to the rationales for my various little techniques (especially "piece diversity", where you try to keep the top of your piles well-mixed so that every 2-color falling pill has a place to go) most of it is well ingrained and under my fingers, even though some attention is still needed to play well, and if I get frustrated with losing I usually have a higher gear of focus I can engage.
I suppose I have some of the same with performing music, but only at low levels. If my facilities start to decline thanks to age and alzheimer's, I suspect one of the last things to go will be the pattern for playing a basic scale on a brass instrument:
Open, 1-3, 1-2, 1, Open, 1-2, 2, Open.
And I suppose pro musicians who've all done a MUCH better job of practicing than I have have more fully internalized much deeper musical concepts and tropes.
There are probably broad patterns to programming that are the same way, even though I feel like I'm more reliant on quick-lookups for specific function names than ever.
Of course, "Zen and the Art of Archery" also emphasizes intense repetition under the guidance of a master teacher. I suppose that's to mitigate the risk many of these pursuits share, where you might just end up deeply engraving how to do the thing suboptimally. There are even fewer examples of that in my life, I'd say. In part, it's a weird matter of faith - how do you know someone is that kind of expert? Not just an expert at the skill, but also in the pedagogy to get other people there? Between healthy skepticism and less healthy pride and ego, it's tough to find...