I honestly don't know. I rarely pay attention to these kind of things. I didn't even know how many posts I had until I happened to glance at the words "Planted Tank Guru" and saw that I'm just over 2000 posts. So I'm guessing #2000 was when I graduated from wannabe status.
All I know is for the longest time it said "wannabe guru" and it made me chuckle.
And you know the crazy part? The moment I posted my 2000th post, I instantly felt like a guru! I instantly had all the answers. It was like magic! So, the numbers don't lie folks. The username subtitles DO NOT LIE!