I've answered this a while ago
I started active music listening in 2004 or 2005, with Hardcore, Progressive Trance, Psytrance, Happy Hardcore and that kind of stuff. Downtempo and Ambient I started listening to a few years back. The latter ones I more love nowadays, but the first ones should still count, especially Psytrance and Hardcore lately, and Progressive Trance by summers.
TL;DR when I was 9 or 10
same (Your age when you fist listen to a genre that now you love?)