I'm the complete opposite. I'm convinced my brain has some kind of overly aggressive internal garbage collection. Knowledge/tools that I haven't derived utility/benefit from get purged. I will say that something I've book-learned in the past can be re-learned more rapidly if I run into that problem in the future, but it's grossly inefficient and of little benefit.

I have found this to be true, but I think the key to absorbing things is to figure out how to associate it with benefit/utility.

I can see it going both ways, depending on how narrowly you define "new thing."

I have never written a program in Go but could probably pick it up through reading, because I have years of experience with other languages. But I pity the poor programmer trying to set up everything for the first time, alone.

Or my first try at home repair was daunting. But now that I have fixed a few simple things I have a better feel for it and might be okay learning the next thing with a book.

I think this is partly why some people like watching Youtube videos and others just want an article.

Doesn't that mean it doesn't stick immediately?

I've always assumed that's because you're sort of mulling it over in the back of your head.

If I understood it the first time, it usually sticks very well. I'm refraining from saying completely and always because it's obviously not an absolute.

What I meant with that last sentence was that even for material I did not understand well (because it seemed to go over my head), I usually still finish reading the material, trying to absorb a very handwavey gist or general structure of the idea, avoiding the need for closure and leaving large chunks unclear. Then, after several days, I often find that I now almost magically understand it because it just clicked without me even being aware of it.

It is highly dependent on the person (and book) indeed. I always preferred book reading and learning like that. Carefully thinking it through and then working on it. Worked well so far.

But over time (especially reading material from my kids classes) I see a lot of tiny mistakes, left out information, or imprecise statements which make me wonder whether I just did not see that before or quality of school books etc did degrade.

I've found I need both myself. I learn best when I read something and then shortly after get practical practice using what I just read. I find i'll forget little details of what I read if I don't use it right away, but they'll stick if I do something with it right away.

I agree, I've come to appreciate the practical aspects too and feel like I'm now using them synergistically. I'd still say theoretical reading is my primary learning mode.