I started at 11! My brother let me play a druid on his account. We shared that account until he moved out, shortly before Kunark came out.
For my birthday, or maybe Christmas, that year he bought me my own account and Kunark!
I remember being 12 or 13 and my brother saying to me, with clear surprise, that he was proud at how well I played my Bard. In the OT, I had a cat mezzed, another add charmed and kept other songs up for the group the entire time. Twisting before melody like a boss.
By 14 I had been swayed away by newer games with better graphics and less hard-core mechanics. But EQ was the game I came back to more often then not.