Members forgetting their usernames or passwords is a common problem on any site, so don't feel bad if this happens to you.  Fortunately, there is an easy solution.  

If you log in with an incorrect username or password, it will take you to a screen with a message saying Username or Password Not Known.  To recover your password, simply click on the "I've forgotten my password link."  Here is a direct link to that page.  Once you reach that page, fill out the required fields and press the "Proceed" button.  This will send an email with password recovery information within a few minutes, if not instantly.  Simply follow instructions in the email to recover your username or password.