I recognized patterns, but I never knew that there was a whole tradition of writing music in a way that set forth themes, developed them, and followed patterns of modulation. I could play classical concertos from memory, but I had no idea when I was in the exposition or the development section of a movement, or, for that matter, what a development section actually was. Maybe everyone assumed I knew.
At Juilliard our "Literature and Materials of Music" course might have included the formal analysis of a few songs, but I believe we spent most of our time on harmonic analysis. What good is harmonic analysis if it is not taught in a musical and preferably formal context? Maybe the people who designed that course assumed that everyone knew about form already.
I thought I knew a lot about music when I was in my 20s and 30s. I know that I played a lot of music when I was a student and when I was in the working world, but I feel like I missed out on a great deal of the experience of listening and playing because I was unaware of what was actually happening in the music. Somehow my music history courses at Juilliard managed to skip over the idea of teaching anything about classical forms. I know that the 1970s was a time when it was "hip" to consider non-formal aspects of music, but I believe it is really a disservice to music students not to teach the basic tools for interpreting music intelligently (and that's what most students are in music school to learn) in theory and music history classes.
I only began to understand form when I started writing music, and I only started writing music seriously when I was close to 40. When I read Edward Cone's Musical Form and Musical Performance and Donald Francis Tovey's The Forms of Music, I started to understand what I wish I had learned as a child or as a young adult. Maybe I should have asked my brothers what they were talking about.