I think, actually, the only part where I was confused at all was trying to remember whose dream they were in after a while, but I guess that was hardly relevant. I figured it out, though. It's all good.
And people need to stop looking into things too much. It's a movie. If you're too busy trying to figure out the 'why' of it all that you lose the enjoyment of the experience, you're doing it wrong. This isn't even close to being the quintessential psychological mind-fuck film, and after everything everyone was saying, I expected it to be and was very disappointed. If you have any understanding of cause-and-effect, you've got this shit in the bag.
It was still a really good movie, though. Just wanted to feel confused, I guess.