Worst still, you are just a newbie (on forum) and there isn’t much need to be worked up on changing your name. Most of those that have happened to need this change in the past are those that have attained certain rank on the forum and have archived so much with an account not to want a different account but for some reason, don’t want to be known by same username from account creation.
The most common reason for a name change is security risk. If a newbie or legendary members needs a name change for their privacy, the admin would attend to it promptly. If it's just for aesthetics, it would take a long while and you'll need to be prominent enough, even that might not be enough.
The most recent newbie I can remember who got a name change appeal granted was a user that opened an account using their email as the username. That presented an obvious security risk which theymos attended to.
Theymos is quick to handle issues concerning users privacy. It doesn’t matter your rank or reputation, if it poses a risk of losing your privacy, Theymos will handle it. I also remember the case of newbie who used his real name to register his bitcointalk account. He soon realized his mistake and requested for change of username, and got his account username changed.