I’m a little amazed at how fast “American Horror Story” rocketed into the pop-culture consciousness. I shouldn’t be. It’s a Ryan Murphy show, after all, and Ryan is eerily attuned to what will work on television. Tonight is the show’s finale: I’m a little amazed by that, too. It’s not even Christmas, and a new show is done? That’s television now: shows have only 6 or 10 episodes and they’re finished — at least until next season!