Something there should be a word for:

The moment of confusion that occurs when you expect one thing and get another. For example, If you are very used to hearing a song on a compilation CD, you grow to expect the next song, perhaps even beginning to sing it in your head in the little silent siesta between tracks. When you hear the song on the original album, it is followed by an entirely different song, momentarily disorienting you. This would also apply to taking a big slurp of what you think is going to be mineral water, but which is in fact Zima, or industrial cleanser.