Consider the music that you liked when aged fifteen to seventeen inclusive. I mean bands whose records you wanted to buy or whose gigs you went to. It is unlikely that your tastes were exhaustive. What is important is whether the music that you liked then is music that you still enjoy as much today as the music that you like now. Are you still as excited and thrilled by the music you liked at that age? Certainly, your tastes and knowledge have probably expanded greatly but that should not replace what you liked previously.
The test for true love of music is: Retrospectively, do you think that the music you liked when aged fifteen to seventeen is good?
N.B. This is not a taste of how "cool" or otherwise your tastes were at that age.