"The great aim of education is not knowledge but action."
I was always taught that if you want to evaluate your belief systems examine your actions and not your thoughts.
If you are an aspiring orchestral musician and you don't play your first notes of the day until 11:00 then you believe that you don't need to start playing early in the morning in order to win a job.
If you are a music education major who doesn't record yourself conducting except when you are required to for a class then you believe you can become a good enough conductor to get and keep a top job without doing so.
If you are a musician who is not great at sight reading and you don't practice it each and every day then you believe that you will eventually get a break in the business that will not involve needing to be great at sight reading.
Believe your actions over your words.