Let's be honest, how many of us really understood what Computer Science @ CMU was before 15-251 ;)
Coding is the reason I was interested in Computer Science and I also happened to like what Computer Science was after diving into the major. It's totally fine for a high schooler to have this view, I think we forget what high school us really looked like back then. It's almost impossible for most high schoolers to understand all of the theory and mathematics that comes with the major.
From a current CMU student, best of luck to you Alex!