Is It Possible to Understand the Future?

A couple of days ago I watched a movie called A Single Man in my TCOM class. The basic premise of it is a man (the lovely Colin Firth), so heartbroken over the loss of a loved one (Matthew Goode), that he spends the entirety of the movie either preparing for his suicide or flashing back to better times. One of the big messages in the film was the idea that when everything becomes clear, when all the troubles and problems of your life either dissolve or become solved, that is when you will die. This is because there is nothing left to live for really. There is nothing left for you to figure out. My professor, after the movie was over, made a joke that he gets really worried whenever he feels like he's figured something  out because then he thinks, "Shoot! Am I about to die?" So this idea is an interesting one to ponder. I can relate it back to To The Lighthouse because this clarity could in a way be 'Z'.

However, when looking at a quote from Leaves of Grass, which says that "The past and the present wilt - I have filled them, emptied them,/And proceed to fill my next fold of the future" it offers an opposing view. I get the impression that to fill and to empty the past and present is to come to an understanding with them. Therefore, to understand them is to reach clarity, and according to A Single Man that's the end. But Whitman says that he proceeds to fill the future. Does that mean that when you reach clarity in your life it is impossible to have a future? Or is it just impossible to understand the future?