> But it didn't help me - or anyone I know - to be able to sight sing, for instance.

I remember asking my mother how she could sight sing so easily (she got her degree in music). She told me you have to practice it intentionally like you practice playing your instrument. It's always difficult at first. Blew my mind. I was hoping there was a lazy way to learn, so I would just automatically become a sight singer from practicing my instrument, but alas, no.