Concepts are mental tools

Concepts are mental tools, they do not have independent reality. Do not ask if a concept is "real", ask if it is useful.

Definitions of words are not objective; words are tools for communicating with others. They are tools for altering the mental states of other people.

Similarly, concepts are not objective; they do not necessarily refer to concrete objects in the world. They are tools for understanding the world.

Freud had a model of the psyche as id, ego and superego. Is this "true"? You can't cut open a brain and point to them. Does the theory make useful predictions? They don't have to be right every time, just better than chance, until a better model comes along. I don't say "falsifiable" because predictions don't have to be right every time.

If I say the brain has a cerebellum, this isn't a theory which makes predictions. But it is still a useful concept. I can talk about cerebellums and people will know what I am referring to. This does not rely on "cerebellum" referring to a concrete object. Objects are abstractions built out of atoms.

If I have a piece of software, a "black box", you can interrogate it and gain an idea of its behaviour. You might start to develop a theory of how it works, using abstract concepts like "id" and "ego". These might even match the abstract concepts in the mind of the person who wrote the software, or the abstract concepts you might develop if you read the source code and tried to understand it.

However, if you can never look at the source code, there always remains the possibility that your predictions are falsified. That is, even if you appear to be able to make perfect predictions, you might be wrong in the future. Again, even imperfect predictions can be better than chance.

Reality is like the black box. Your abstractions are not real, they are prediction generators that might work most of the time but could always turn out to be wrong.