I can see from your response that there are a number of points that I need to clarify.

Firstly, I am not at all surprised that you, personally, do not feel that your position has been undermined, and I don't suppose you ever will, but one of the themes of my response is that neither your intuition, nor that of like-minded people, is particularly persuasive; for that, you need something that would give a skeptic persuasive reasons for abandoning their skepticism.

From your statement "causality is not likeness", I see that I need to clarify the point I made in my penultimate paragraph. To do so, we need to go back to your second post in this thread [1], and in particular, to the paragraph beginning "for a thought to be about reality, there must be something about that thought that makes it about reality... And for the thought to be about the reality, there must in one way or another be similarity between thought and reality."

The point in my penultimate paragraph is this: If we suppose that there is a causal flow from the real world to brain states via the sense organs, and adopt the premise that (changes in) mental states are caused by (changes in) brain states, then we have at least the outlines of an answer to your tacit initial question (what is it that makes a thought being one about reality?) that does not invoke or depend on any concept of likeness or similarity. In what I quoted above, you certainly seem to be saying that the only thing that could make a thought about reality is that it has a similarity (in some nebulous sense, at least) to reality, but here we have another way for a thought to be about reality that does not depend on likeness in any sense.

At this point, I can imagine someone saying "... but this causal chain could well result in brain states that are, in some sense, similar to reality." I don't dispute this, as I am not arguing against the idea that such a similarity can be seen, I am arguing that a link between reality and thoughts can plausibly be postulated without an appeal to similarity or likeness in any sense, let alone an appeal to a likeness about which it is asserted, apparently purely on the basis of intuition, that cannot possibly be physical in any sense.

In the light of the above, my misunderstanding of what you were calling complex seems moot - an understanding of causality may potentially lead us to being able to say, with some specificity, in what way thoughts are similar to reality, so it is not inconsistent with the claim that there are no complex issues in seeing that there must be a similarity, even if it does not do anything to endorse that view. In the same way, it is consistent with your claim that the only likeness for materialism can be a physical likeness, without actually requiring it.

The above physicalist story has another thing going for it: it contains at least the outlines of a possible explanation of how thoughts are related to reality, while your story does not - as far as I can tell, it is confined to saying that whatever it is, it can't be physical. If you have anything affirmative to say about how thoughts come to resemble reality and what the similarity is, now would be a good time to present it.

Your response to my CD analogy does not need much attention, as it is just an analogy, but I see I did not make it clear what point I was aiming at, which is that while "how can it be that..." questions can be insightful when the person asking has a good grasp of what is going on, they can merely reflect ignorance when the questioner lacks that understanding - and when it comes to how the mind works, we are all ignorant to a considerable degree.

By now it should be clear that what you claim in your final paragraph is wrong: in order to show that your argument has failed to make its case, I neither need to show how there can be likeness that is not physical likeness if materialism is true, and nor do I need to show that likeness is not necessary for a thought to be about reality. On the contrary, you have chosen to make a strong claim - essentially that the mind cannot possibly be the result of physical processes - and to sustain that, you need more than arguments grounded in appeals to intuition about how things either must or cannot be. In particular, anything resembling 'so prove me wrong' would amount to burden-shifting, and while we are about it, the alternative to 'the mind cannot be a physical phenomenon' is not 'the mind must be a physical phenomenon', it is 'the mind might be a physical phenomenon' (something that I believe is probably true, but which I do not claim to know.)

[1] https://news.ycombinator.com/item?id=42312450