Previewnesia 

The state of forgetting what movie you actually came to watch due to the excessive advertisements, trailers, previews, messages to silence one's cell phone, etc. that occur between the advertised start time of a movie and the time the feature begins. Usually, the state of Previewnesia is experienced right as the feature is (finally!) about to begin and you realize you can't remember what movie you are about to see.

Jim (to his date, Elaine): "Hey babe, do you remember what movie we are about to see? I've got previewnesia"
Elaine: "No I've got previewnesia too, I can't remember. Maybe it's Goonies 2 or Avengers 4?"

Previewnesia by RATTnroll January 18, 2015