Aren't we humans functioning in the same way, failing for 10% (take a random number) whatever we learn because we can forget, or be tired, or distracted? And what is the practical effect of "actual understanding" other than actually getting the 90% right (or more, or less, whatever)? I cannot tell what's inside my neighbor's head so for all practical matters they could be an AI, so why should I care whether the AI has a real understanding (good luck proving that) or not? I only care whether they take away enough jobs (mine included) that I cannot life a peaceful life anymore because it sends me foraging for roots or I must defend my roots parcel against hungry foragers. And for AI to achieve that it definitely doesn't need "actual understanding" just following some less or better formulated goals and having the right tools under their "hands".
What I want to say is, yeah fascinating topic about real understanding, but I think we have more pressing issues.