Somewhere early on I was given the impression that all major keys on the piano are interchangeable. Ha! Not so, McGee!
Children who are encouraged to notice how different they are can open a book of sonatas and get into subject matter before they have played a note.
Consider this: Are all books interchangeable? Doesn't it matter that you know the difference between fiction and non-fiction? Admittedly the categories have gotten out of hand in terms of book publishing and it is impossible to imagine a book that cannot be strictly departmentalized. My little book, What Might It Mean? An Uncommon Glossary of Musical Terms and Concepts for the Stuck, Bored, and Curious* is funny and yet dead serious, for adults young and old, for serious musicians as well as amateurs--even writers who don't know anything about music have found it insightful concerning criticism. Because it cannot be categorized I had to publish it myself.
The ability to tell the difference between something of specific relevance and something more general is a sign that one knows how to read, no?
*It is available on line, or you can contact me for a copy.