when i'm expecting something to go one way and it goes another i am always unhappy with the results. Even if the result on its own would be considered positive. I reached for a cream soda, someone had switched one of the bottles in the 6 pack, i opened and drank it, not seeing it wasn't cream soda. It tasted terrible. Turned out to be black cherry soda. I love black cherry soda, but not when i'm expecting a cream soda.
i am not trying to make a moral statement or some philosophical revelation. but the moral to the story is, live without expectation and you'll be disappointed less often.