When i was 15 or 14?
I don't even listen to them, but a very good friend wanted me to come and I happily agreed.
We're still friends!
But if you consider operas concerts, then my first concert was, when I was 9 or 10. My primary school had organised a trip for all 4th graders to go to see an opera of hansel and gretel, and it was boring as hell 💀