Many of the questions revolve around imparting correct understanding. Often, even with seemingly good instruction, wrong understanding still occurs. There are particular concepts in CS that cause this most often, things like assignment and complex decision structures (not to mention indirection). So one issue is how to convey the right impression, in a reliable way.
However, "I have a doubt", as one of my former students would say. I sometimes wonder if any two people really understand an idea the same way? The old conundrum children tell each other is: how can we know if the way that you see green is how I see it? We cannot. More complexly, how can we know that how you understand a word is how I understand it? We cannot. Like in Philosophy, you don't get truth, you get outcomes. If you use a word in a way that makes no sense whatsoever, I might venture to you that you have misunderstood it. But what went wrong in the learning?
At times I think about how the brain and mind work, and I am tempted to state that every person actually has a unique, unsharable, unconveyable set of beliefs (we can't actually know anything, remember?), so how can we know that two people 'really' see something the same way, let alone impart an understanding to them? Things can be learned, clearly, but to what extent can they be taught? I am tempted to say: "Not at all." We know that lecturing does not work. Textbooks seem unhelpful. We are left with self-discovery, whether shaped in a classroom or not, but individual and unique all the same.
Sometimes it shapes the concepts rightly, and sometimes it doesn't. I am not sure if this process can be improved upon. I am sure you disagree. But are we even talking about the same thing? Aporia.