Amusing coincidence. I also wanted to be a rock star, or at least a successful working musician. My mom also talked me out of it. Her argument was: If there's no way to learn it in school, then go to school anyway and learn something fun, like math. Then you can still be a rock star. Or a programmer, since I had already learned programming.
So I went to college as a math major, and eventually ended up with a physics degree.
I still play music, but not full time, and with the comfort of supporting myself with a day job.