...right away, that is.
Transitioning from high school to a college-level music program is tough. Everyone who gets into music school was the top dog in their band program back home. When faced with a level playing field for the first time, a lot of music students try to hide the fact that there are gaps in their knowledge. Some people are weak in music theory, others don't know much about music history. Some even manage to get in without knowing all their scales from memory.
At the undergraduate level, this is normal.
Bachelor-level music programs exist to teach future musicians how to be musicians, and that means instruction in theory, history, piano, and ear training. Anyone who already has 100% proficiency in these areas is wasting their time and money at college and should start auditioning for orchestras.
Knowing everything really isn't as important as wanting to know everything.
Music professors are looking for students with potential, students who will be a pleasure to work with for four years, students whose minds are open and who are willing to change the way they play if the new way is better. Most professors have no interest in dealing with jaded students who don't think there's anything left to learn.
So when you get to music school, remember this: you can be stubborn, think you know everything, and remain only as good as you were when you were a senior in high school.
OR you can be open to the idea that there are musical concepts you haven't considered and things you need to know but haven't even heard of, and you can continue to grow and improve for the rest of your life.
Guess who comes out on top?