Seriously--take heed of this, OP, because it isn't easy to get your username changed and your chances of convincing Theymos to do it for you are pretty much nil.  I requested a name change not too long ago and had tons of support from the community, but I was summarily ignored and my username is the same as it was when I registered.

Fortunately you've realized you're not happy with your username while you're still a very junior member here.  It's easy enough to just create a new account with whatever new name you like, so just do that.