If you've seen The Fountain, chances are you either found it a work of genius or, like I did, an interesting failure. It's a love story between a man, a woman, and a tree; with the characters somehow living three separate lifetimes: past, present, and future. Darren Aronofsky has indicated that only the present-day storyline might be real; the past story is the book that Rachel Weisz' character is writing, and the future might be a fantasy or some kind of astral projection. But of course it's one of those films that's open-ended enough to have room for different theories on it.
I personally found it intriguing but ultimately disappointing, until my brilliant wife rescued it for me with a completely different take on the story. She watched it and saw a single timeline with the same characters over hundreds of years. Which is slightly wackier, but as it turns out I like her version better. Aronofsky's version, a letdown. Faith Fennessey's version, one of the greatest sci-fi films I've ever seen.
If you'll be so kind as to follow me to the comments section, I'll break it down and you can see if you agree. (Spoilers ahead. But go ahead and read it, it's not like I can stop you. Ruin the movie for yourself if you want, tough guy.)