That's probably because people themselves are bad at predicting their own choices. Depending on mood, the day, even your hydration level, you can feel vastly d

That's probably because people themselves are bad at predicting their own choices. Depending on mood, the day, even your hydration level, you can feel vastly different about something. I believe this was a conclusion of the Netflix Prize contest, getting much more accurate at predictions was hard because people would not reliably rate a movie the same.