I think this might come down to what instrument you used. I played clarinet for several years and could never hear the notes in my head, I just associated them with fingerings. Now, I could tell if a note was in tune, but only by hearing it.

On the other hand, if you’re a vocalist of some kind, you need to be able to sing the correct note based on the sheet music. The closest I ever got was getting the correct key and then basically shifting pitch based on whatever key I’m in.

I never took any music theory classes so I’m mostly just talking from my own personal experience