99% of the time this happens to me, it's because I'm watching it with other people and I walk out of the room to do something else because they annoy me. I just have certain movie watching rituals that I can't break otherwise I can't enjoy the movie. For instance, watching a flick with my father. I always have enough to drink to last me through a movie beside me. He has to get up four or five times during a movie to get another drink and it completely distracts me.
Every now and then, though, this happens because I'll borrow/buy a movie and it has a bad place in it. I have so many movies I need to watch that by the time I replace it it's normally moved way down my list.
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