A few years ago, a friend mentioned to me: "One problem with being good at learning from a book is, you tend to think you've mastered something just because you read about it."
The more I've thought about that over the last few years, the more I've recognized that as the explanation for all sorts of weird things I've seen.
I remember when I started teaching high school, all sorts of well-meaning but clueless parents were full of suggestions to "help". These suggestions ranged from helpful to stupid, but all centered in a fundamentally broken model of learning.
I taught math and physics, which made me fairly unpopular, not only with students, but also with parents who'd heretofore never had to contemplate the possibility that Jr. wasn't the next Nobel laureate. So they naturally had multitudinous suggestions to improve my teaching. (Because "Johnny needs to work harder" couldn't possibly be it.) I remember one parent in particular was full of praise for a video series her son found helpful in learning Algebra: I even showed the class an episode or two (at her suggestion). I was unable to explain algebra to him, but those videos worked wonders! Or so she thought...
What I didn't consider at the time was, the videos almost certainly would appear to do a good job of teaching math, because they didn't give feedback. That is, anyone can watch a video and say, "Now I understand!" The hard part about being a math teacher is, you give homework, which is tantamount to demanding proof. And that's where life gets difficult.
As I've gotten older ("Too soon oldt, too late schmart"), I've seen that the only proof is in doing. Like those unfortunate students of mine, I've spent a good deal of my life convincing myself I've mastered something contrary to the available evidence.
I've recently decided to learn how to type. You have no idea how painful this is, but there's a certain relief to learning to do something right, to admit I really don't know; but I'm ready to learn.
I sincerely hope that was the experience of those poor kids I taught way back when too.