"But he human does not understand that 很好 represents an assertion that he is feeling good"
This is an argument about depth and nuance. A speaker can know:
a) The response fits (observe people say it)
b) Why the response fits, superficially (很 means "very" and 好 means "good")
c) The subtext of the response, both superficially and academically (Chinese people don't actually talk like this in most contexts, it's like saying "how do you do?". The response "very good" is a direct translation of English social norms and is also inappropriate for native Chinese culture. The subtext strongly indicates a non-native speaker with a poor colloquial grasp of the language. Understanding the radicals, etymology and cultural history of each character, related nuance: should the response be a play on 好's radicals of mother/child? etc etc)
The depth of c is neigh unlimited. People with an exceptionally strong ability in this area are called poets.
It is possible to simulate all of these things. LLMs are surprisingly good at tone and subtext, and are ever improving in these predictive areas.
Importantly: While the translating human may not agree or embody the meaning or subtext of the translation. I say "I'm fine" with I'm not fine literally all the time. It's extremely common for humans alone to say things they don't agree with, and for humans alone to express things that they don't fully understand. For a great example of this, consider psychoanalysis: An entire field of practice in large part dedicated to helping people understand what they really mean when they say things (Why did you say you're fine when you're not fine? Let's talk about your choices ...). It is extremely common for human beings to go through the motions of communication without being truly aware of what exactly they're communicating, and why. In fact, no one has a complete grasp of category "C".
Particular disabilities can draw these types of limited awareness and mimicry by humans into extremely sharp contrast.
"And the idea that understanding of how you're feeling - the sentiment conveyed to the interlocutor in Chinese - is synonymous with knowing which bookshelf to find continuations where 很好 has been invoked is far too ludicrous to need addressing."
I don't agree. It's not ludicrous, and as LLMs show it's merely an issue of having a bookshelf of sufficient size and complexity. That's the entire point!
Furthermore, this kind of pattern matching is probably how the majority of uneducated people actually communicate. The majority of human beings are reactive. It's our natural state. Mindful, thoughtful communications are a product of intensive training and education and even then a significant portion of human communications are relatively thoughtless.
It is a fallacy to assume otherwise.
It is also a fallacy to assume that human brains are a single reasoning entity, when it's well established that this is not how brains operate. Freud introduced the rider and horse model for cognition a century ago, and more recent discoveries underscore that the brain cannot be reasonably viewed as a single cohesive thought producing entity. Humans act and react for all sorts of reasons.
Finally, it is a fallacy to assume that humans aren't often parroting language that they've seen others use without understanding what it means. This is extremely common, for example people who learn phrases or definitions incorrectly because humans learn language largely by inference. Sometimes we infer incorrectly and for all "intensive purposes" this is the same dynamic -- if you'll pardon the exemplary pun.
In a discussion around the nature of cognition and understanding as it applies to tools it makes no sense whatsoever to introduce a hybrid human/tool scenario and then fail to address that the combined system of a human and their tool might be considered to have an understanding, even if the small part of the brain dealing with what we call consciousness doesn't incorporate all of that information directly.
"[1]and ironically, I also don't speak Chinese " Ironically I do speak Chinese, although at a fairly basic level (HSK2-3 or so). I've studied fairly casually for about three years. Almost no one says 你好 in real life, though appropriate greetings can be region specific. You might instead to a friend say 你吃了吗?