I’m guessing LuckyGungan read some unfavorable reviews (of which there are many and I understand why) and decided to change his score. Of course, the fun could have worn off fast after the film was over leaving him with a changed opinion.
A bit of both, actually.
You should avoid letting other people’s reviews alter your opinion much on a movie. It makes sense because sometimes people can really bring big aspects of something to your attention, but I try to stay independent of other people’s opinions. After 30 years of being a Japanese scientist, I can tell you that most specimens are happier if they just embrace their own opinions.