I'm logged into my SE account right now that I use on all Stack Exchange network sites. I was looking at my profile on StackOverflow, and noticed a link for me to change my global stack exchange profile. I followed the link (leading here), but strangely, I was no longer logged in. I went to go log in, and first chose to log in with a stack exchange account (I can never remember if I actually signed up here, or if I use google's openID). After the SE login said that it didn't recognize the account, I went to try the google openID login, but it said that I had never registered here.
My ultimate question is, what happened to my account? I'm still using it (as you can see), but stack exchange doesn't seem to recognize me. Am I supposed to register separately from the rest of the SE network?