While an understanding of musical form can certainly enhance the appreciation of music, it is by no means necessary. Music can be enjoyed and appreciated on many different levels, and not everyone needs to have a deep understanding of its structure in order to enjoy it.
Some people may find that their enjoyment of music is heightened by an understanding of its form, while others may find that it is not a factor at all. There are many different ways to appreciate music, and no one way is right or wrong.
Ultimately, the best way to appreciate music is simply to listen to it and enjoy it. Whether or not you understand its form is irrelevant.