I mean, I can look back at art from 3 or 4 years ago and think "wow, yikes, I can't even look at this," but honestly I think that will be true forever.
But the first time I can remember drawing something and feeling really happy with it, like it looked the way I really wanted to, was in middle school, probably around 8th grade (it was a cougar furry). That means I was drawing for about 12-13 years before I hit a moment of feeling like my art was coming out the way I wanted.
(I think that was before I really had a venue to post online, though, so sharing my art with "the world" in that way sort of came later. xD )