I think the best way to answer this question is by explaining my own musical journey because I too just couldn’t stand music theory at first. I started playing the piano when I was just 3 years old, I had just listened to a music piece by Beethoven on the radio a few days prior and begged my mom to let me learn how to play the piano. I remember that I fell in love with playing the piano as soon as I touched the keys, and right after the first piano lesson, my piano teacher spoke to my mom, saying that I am talented as I had changed the melody of a song right in front of her. Within the first 4 years, I went from ABRSM level 1 to level 4, and that’s when my first obstacle appeared, right in front of me: The ABRSM grade 5 music theory exam.
When I first knew that I had to prepare and pass the ABRSM grade 5 music theory exam to advance in my music journey, I was stunned by it, I was thinking to myself, “I’m only good at playing the piano, I don’t know what this ‘theory thing’ had to do with me”, and I wasn’t motivated to learn anything from it because I didn’t know how it would help me in playing the piano. It took almost 4 years before I realized how useful and fun it is to have that knowledge at hand as I started to compose music and have to talk to people and musicians about my work.
You may ask, “Why music theory is important?” Music theory is important because just like the language that you use every day, music theory is the basis on which the language of music is derived from. It is what allows us as musicians to communicate between people and fellow musicians.
Personally, I treat music theory as a tool to learn “musical sentence structure”. After learning the “sentence structure”, you then transfer that message onto the staff (I personally like to think of it as a sheet of blank paper) and let that information be read and understood properly.
You may also ask “why would you say it’s fun?” Personally, it’s not just about understanding the knowledge and being able to use it. For me, the fact that you can make people who have no prior musical knowledge understand how music works and how you are creating/composing music gives me satisfaction, and that’s what makes it “fun.”