I think you’re right. I want to add though that those internal concepts aren’t nebulous things, they’re themselves made up of other dimensions of understanding. Like, i have the word “dog”, and I have an internal concept of a dog, but how exactly is “dog” conceptualized? In terms of senses. It looks like this, feels like this, makes these sounds. And it’s not only the classic 5/6 senses, it’s also time (it acts/moves like this) and hormones and other chemicals (it makes me feel this). Language (it’s called this) is a higher level abstraction of those, but when push comes to shove a word is just one more connection/correlation with dozens of other connected sensations that together form that internal concept