Surprisingly, that's how most jazz musicians learned to play, for the past century: Take the formal lessons that you're supposed to take, then sneak out and learn jazz yourself. White parents were conflicted by the racial biases in music, but even black parents wanted their kids to learn "proper" music as defined by the academe.
My parents had no idea that jazz was my main musical interest.
My parents had no idea that jazz was my main musical interest.