The Fountain - 7/10. I think my rating for this will be a lot higher after a reviewing, or a few for that matter. I've never seen a film like this before, it's something completely different from conventional and even unconventional movie making. I feel like I didn't truly appreciate the film either because of thinking and trying to figure out what was going on most of the time. The ending kind of led me to an interpretation that would allow me to enjoy this another time.
Putting my interpretation in white text to avoid spoilers:
The past is merely the book that the wife has been writing, not actually being real characters. The present and future are in fact real. She really dies, and after she does, his experimentation leads him to find a real cure for disease and aging and he lives forever, into the future. He then tries to "meet up with her" in the future. He also finishes the last chapter of the book for her by taking the sap from the tree but living forever in a different form, accepting mortality in a way. His obsession with living takes over him during and after her death and in the end, he comes to peace with death and subsequently, life as they are two sides of the same coin and very dynamic.