It's possible to change your username? I thought you weren't allowed to so you can stay accountable for what you say on here.
Ah, thanks.Can I change my user name?
The forum software does not let you change your user name.If you mistyped your user name while registering, typed a user name longer than 25 characters that was then truncated, or mistakenly tried ...macrumors.zendesk.com
Here is a FAQ that should answer your questions.
tl;dr You can request a username change. (But read the FAQ first)