Mr Aranofsky doesn\'t write or direct terribly obvious or always easy to interpret movies though, and that\'s what makes his stuff so appealing to me. It\'s the three stories that make The Fountain intriguing, rather than one tale stating things more obviously.
For me it is really only one story anyway, and if you haven\'t seen it it\'s probably best not to read on because here is my interpretation.
It\'s set in the present and about Izzi dying, and Tom not spending time with her in her last days, but instead obsessing about finding a cure, and missing out on spending those last days with her.
The bit in the past is not a reality to me, it\'s a representation of Izzi\'s book, and what she thinks of her man. The bit in the future is Tommy\'s continuation of that book, but from the mind of a scientist rather than a romantic, and gives something of an insight into his feelings of loss and how he has realised his quest for a cure was futile, and he should have spent the time with Izzi.
But that\'s just what I think of it, there are lots of other equally valid responses and reactions, and I think it would be totally unreasonable to say that your take is wrong. I just strongly disagree with it!