I enjoy slow burn movies, especially mystery, but this one just takes it to a whole new level. Previous comments are right, it's not for everyone. I just felt there were a lot of unnecessary scenes spent peeing, masturbating and doing god knows what. It's really sickening and hard to watch. There's so little dialogue and the BGM is so dull. Everything is so quiet that you could fall asleep even though a murder was taking place or there was an explosion. It took me three days to finish this movie bcoz everytime it starts I fall asleep. I was willing to continue bcoz I'm familiar with the pace and I know it requires attention to pick up details but an entire hour+ to wait for things to pick up in a movie of 2+ hours is just too much. As for the climax, I know that it's a trend to leave a lot of questions to be answered by the audience themselves but unfortunately I couldn't really connect the dots in the end and still had to go look it up to understand, really sad.
I should have known better since "old boy" was also recommended by the same blog.