A new theory about the movie *Spoilers!!!
Alright, most of us have come to the same conclusion about the film...as well as most critics. But I was thinking about an alternate scenario that hasn't been considered. **Spoiler warning, again!:
What if Kang did NOT kill his ex-boss or his girlfriend? What if he never really had a girlfriend after his wife died in the plane crash? In that case, he would have made her up and imagined a fake character as a means to forget about his wife...hence, why Min (who is really Kang's wife but has another identity representing Kang's repression of his wife) whispers that she hopes Kang remembers her when he enters the door in the cave. Look at what happens when he first meets Su-Yeong at the karaoke bar. She tells him that they've met before and that he hasn't changed a bit. Kang's reaction to this revelation is to be oblivious about it. When he sees that he might have killed his ex-boss and his girlfriend, I see it merely as him confusing what he saw earlier, when he was a child...when he might have seen his dad killing his wife and her lover. Furthermore, when Min asks Kang if he finally realizes what's going on, he sees her momentarily transform into his girlfriend. That's his way of fighting the memory of his wife because it's too painful for him. In short, I think he's an emotionally disturbed person and may have been that way even when his wife was alive. That incident he saw as a child simply tainted his life ever since. That is why he keeps revisiting the Spider Forest; because that is where he used to live and that is where he became emotionally scarred. Therefore, I think it is very possible he never killed anyone nor had a girlfriend after his wife's death. He is simply trying to lead an imaginary life but it keeps leading into roadblocks. Him getting hit by that car could have been his way of taking the cheap way out by committing suicide. That is, until the end, when he might finally start to cope with his wife's death, rationally. Thoughts? By the way, I'm not married to this theory...but I think it could be possible. I loved this movie, though.