[proposicion47]

Wait until you learn about live beyond 12TET

In short: no you're factually wrong. Human ear can discern smaller pitch changes and there actually music composed on smaller subdivisions than 12

For instance https://en.wikipedia.org/wiki/19_equal_temperament

You can check done pieces on YouTube.

Yes it sounds unusual. Yes it sounds strange. But thats just because you've been conditioned to listen 12 tet all your life.

But saying 12 notes because we can't perceive smaller changes is, again, wrong and there's actual counterexamples of music done with smaller changes

[tarentel]

While you are 100% correct a very simple counter example to the op that a lot of people have likely heard in their life is someone tuning a guitar. It would have saved me a lot of time if people couldn't tell the difference. :D

[john61]

You can test this in the Vienna museum of music. There is a live demonstration with a headphone and with two knobs for the frequency of two separate tones playing together. Also, it visually shows the pitch of those two. If you go below the 12 tone pitch you hear only one tone, near the 12 tone pitch this one tone becomes suddenly to two separate tones.