But what I am against is the idea that some interpret Wittgenstein's “meaning is use” as being that 100% of our thinking derives from language and society. — RussellA

Yes, people too often assume that language is about communication and has no other uses. That's not true.

“I am in pain” refers to being in hidden inner pain, whilst “ouch” refers to the behaviour of outward observable grimacing. In this sense, as they refer to different things, they are not synonyms. — RussellA

"Ouch!" isn't part of language, so it can't refer to anything. You should think of it alongside grimacing. Both are, one might say, expressions of pain. "
If "I am in pain" refers to hidden inner pain, then, surely, it is not hidden. "I am in pain" is like "ouch" and grimacing in many ways, which is why Wittgenstein insists that it is an expression of pain. The complication, which, I think he does not deal with because it is not relevant to his focus in that discussion, is that it is also like "S is in pain"; it plays into the standard structures that usually apply when se speak of knowledge.

You are assuming we can directly interact with outer facts. A Direct Realist would agree, but an Indirect Realist would disagree. An Indirect Realist would say that we are directly interacting with an appearance of what we assume to be outer facts. — RussellA

I am not assuming any particular theory about perception or facts. All I am assuming is that there are such things, and that, one way or another, we interact with them. I feel that direct and indirect realism might be regarded as off-topic on this thread.

So, yes, the meaning of "beetle" preceeds you, and you learn it, and then you know it, and based on that knowledge you use it. — Dawnstorm

Person A sees a beetle in the world which causes a thought in their mind of a beetle. It may be that when they see a beetle in the world they also see alongside it in the world the name “beetle”. They can then begin to associate their private thought of a beetle with the public name “beetle”.

Person B sees the same beetle in the world which causes a thought in their mind of a beetle. It may be that when they see a beetle in the world they also see alongside it in the world the name “beetle”. They can then begin to associate their private thought of a beetle with the public name “beetle”.

Person A can then say “I saw a beetle” to person B, who will then know what person A means.

It may well be that my-red-is-your-green, and the beetle in person A’s mind is different to the beetle in person B’s mind, but as regards language this doesn't matter because the common factor is the beetle in the world, which is the same for both persons A and B.

Language is not communicating the private thought of person A to person B, because their private thoughts may be different, but is communicating the knowledge to person B that person A is thinking of the same observable, empirical fact in the world.

Language can be used to communicate knowledge between people because public facts have private meanings.
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When you know that the water in this tub is 36° Celsius, then that knowledge has no influence at all on the temperature. — Dawnstorm

If there is a beetle in the world, this is a public fact, independent of private thoughts.
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When you know the word "beetle" means [beetle] (square bracket for the private meaning that - according to Wittgenstein - drops out - if I'm not mistaken), then you use the word "beetle" to mean {beetle} (squiggly brackets for a token in a language game). — Dawnstorm

On the one hand the private beetle drops out of the language game, but on the other hand the private beetle cannot drop out altogether otherwise the mind would be an empty blankness, and there would not be any language game at all.

My concept of “slab” must be similar to yours, but cannot be the same as yours, because we have experienced different Forms of Life.

Because we have learnt our concepts of “slab” through an extensive personal Form of Life, our concepts are too complex to be defined.

Our concepts of “slab” probably generally overlap, but it is unavoidable that sometimes my concept of “slab” will be different to yours. — RussellA

I would not use the word "concept" here. I think concepts are logical structures with formal rules. Instead, we both know how to use the word, though our particular instances of use will vary. Where we all overlap in usage, we have what is required to make a generalization (inductive conclusion) which may serve as a dictionary definition. What I think, is that if someone states particular criteria, or rules governing the use of the word, for the purpose of a logical procedure, then we have what is required for a "concept". Notice though, that I am stipulating such rules in this case, proposing a restriction to the way that you use the word "concept".

If "I am in pain" refers to hidden inner pain, then, surely, it is not hidden. — Ludwig V

It is possible to refer to hidden things. For example, if I see a broken window, I can say that something caused it to break. What caused the window to break may be unknown, but I can still refer to this unknown something.
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"Ouch!" isn't part of language, so it can't refer to anything. — Ludwig V

I agree that uttering ouch is not part of language, but saying “ouch!” must be part of language. As it is the nature of language that every expression must refer to something, “ouch!” must also refer to something.
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"S is in pain" — Ludwig V

As regards language, there is form and content. How does language work?

The form of language, the symbols used, is as much a physical thing in the world as grimacing, and both are empirically observable. The form of language is as empirically observable in the world as a person’s behaviour, such as grimacing. It is the form that gives clues to the content, in that observing someone grimace gives clues to their being in pain. If, when I feel pain, I instinctively grimace, then when I observe someone also grimacing, it is a reasonable assumption that they also are in pain.

As the form of grimacing gives clues to the inner feeling of being in pain, the form of the linguistic statement “I am in pain” must also gives clues to the inner feeling of being in pain.

This suggests that is the form of the linguistic expression “I am in pain” that gives us clues about the speaker’s inner feelings rather than the content of the linguistic expression “I am in pain”.

I would not use the word "concept" here. I think concepts are logical structures with formal rules. — Metaphysician Undercover

From Wikipedia - Concept

A concept is an abstract idea that serves as a foundation for more concrete principles, thoughts, and beliefs. For example, a basic-level concept would be "chair". A concept is instantiated (reified) by all of its actual or potential instances, whether these are things in the real world or other ideas.

I have never thought of a concept as a logical structure with formal rules. For example, if I think of the concept of a slab, there is no logical structure to my thoughts of slabs and there are no rules limiting my thoughts of slabs.

I was going to say that as well. But you already knew that.