This happened to me; I forgot my exact username because I'm used to it having a space in the middle or my password was a bit unusual or whatever, and when I couldn't log in, I didn't get an option to send a reminder to my email address, which is a feature most sites have.

As it happens, I had to make a new account to get in (which suits me just fine, because I wanted a username change anyway!).

Yeah, this is something I've just realised is a problem after someone came into the chat and said something. I'm sure Mahz will get this up pretty soon. For now, make friends and have a way to get in contact with them outside of the site so they can help you out if you get locked out. ;)