I read those links.
None describes my problem.
Really? You stated that your administrative account has been reduced to that of a subscriber. If you weren't the one who changed it, then one might be inclined to suspect that because you are still running a version of WordPress that has been known to be exploitable for an extended period of time now, it may be your exact problem.
I quickly went to check out my tables in phpmyadmin,
everything looks just fine, the admin is user number one
in the users table.
Indeed. I imagine it is. But, aren't you the administrator? Yet you can no longer log in as an administrator... only a subscriber?
I hadnt logged in to my wordpress in a long while.
Today when I did it using my admin account,
the dashboard shows items as to a regular user.
The logical conclusion is that the administrative account no longer belongs to you. You might want to research some of the information in those links I provided a little further. It may turn out to be nothing, but chances are far greater that your web space has been compromised and your site is no longer controlled by you.
There might also be something of more use located here:
I'll let you refine the search to suit your particular circumstances.