Notes are just a way to write music down. Each note corresponds to a tone. Also, their names repeat themselves in intervals. Take C for example. There's a C placed below the five lines, the deep C, then there a C placed within the five lines, just called C and then there's a C above the five lines, called high C. If you keep going higher or deeper you'll encounter C's again and again.

If you play the deep C and the normal C at the same time, that's what people call an octave. It's just a name for something people found worth talking about. If you only play music and don't talk about music, you can go without ever noticing that this thing is called an octave. Most things about musical theory are like that. Just names for concepts people found worth talking about. But if you don't understand the underlying concept, it's going to be very hard associating the names with anything meaningful.

Music theory is basically full of nerd language. Take for example anime. If you aren't an anime nerd and someone tells you about moe, tsundere, isekai and ecchi you're going to be lost. None of these words are strictly speaking necessary to describe the underlying concepts, but once you understood the concepts, it's very nice to have just one word to describe them, instead of having to spend three sentences. At least if you want to talk to other people about them. You can also go an entire life of watching anime without ever knowing what moe is, despite having an understanding of the underlying concept.

So, really, I don't think you have a mental block, you likely just never had the desire to talk about music theory with others. But whether it's music or anime, there's really no point in talking about it on a nerd level if you don't even play music or watch anime.