Board Thread:General Discussion/@comment-2168225-20130926023356/@comment-1724320-20130926051904

Your userID is a number that is tied to your account forever, which is based on the order that you signed up in (i.e. the first person to register, User:Jasonr, has ID 1). There's no need to write down the number as it's not really useful to you personally, but if you need to find it again you can view the source of a page on Wikia while logged in and search for "wgTrackID".