Simple process, easy to find. Simply click on your username, and go to all comments. Pay attention to the URL in the address bar. It will say something like "show/######/user". Whatever the number is in those symbols is the id number you were when you first created your account.
For example, I am the 453514th account created on ArmorGames
http://armorgames.com/user/asdfwsnfmlk
This was the first normal account created that wasn't a staff member or a game developer of some kind. Of course, he/she is gone now ;-)
So! Tell us your account number and feel the awe of how "antique" or "new" your account is in comparison with other users on AG!
