Although it is not explicit, one gets the feeling that Harold, in the beginning, is not particularly unhappy with his life. He seems content with his regimental existence. It is not until the narration of his profoundly unvarying life begins to play in his ears, detail by wearisome detail, that Harold begins to awake from a lifelong slumber, triggering a transformation that unfolds throughout the film.
But it's not this very strange event or even this new forced consciousness of his mundane life that perpetuates Harold's metamorphosis.
Harold's transformation happens on three levels; sort of a causal hierarchy. At one level, it is sensible to attribute Harold's feelings for Ana as the impetus of his renaissance. After all, love and attraction change people--a universal truth. Think of this as a ground level cause, happening closest to Harold; or, to facilitate getting all philosophical up in here, the material level.
On the other hand, we know that Karen Eiffel is the author of Harold's fate, orchestrating the meeting of his beloved in the first place, making Eiffel an obvious candidate as the driving force of Harold's conversion, or so it would seem. This is the next level--the metaphysical, happening outside of Harold's material world. Eiffel is, for Harold, the cosmic hand of fate or God. But I would like to suggest that neither of these things drive Harold's reanimation as much as a third cause: the news of his immanent death.
This cause can be thought of as happening at the material level--the visceral physiological survival instinct; or the metaphysical level--something within the Soul; or both. But the distinction here is not important. The point is: It is only after Harold learns he is going to die that he begins to truly live.
And, it is all Harold. Eiffel does not write about Harold's relentless pursuit of her, his desperate attempt to change his destiny. This happens outside of Eiffel's knowledge and control. Harold out wills the author of his fate.
I inserted the following clip on this post before I knew what I was going to write, as it is one of my favorite scenes. Fortunately, it fits right in. The oblivious character introduced to us in the beginning of this film could not have possibly aroused the feelings in Ana portrayed in this scene. The man we see here has undergone a profound radical change, establishing the vitality and confidence required to elicit the emotion seen here on Ana's face; a vitality that would not exist had he not been faced with the end of his own existence.
It is Harold's inexorable will to live and the resultant change that cause Ana to fall in love with him. His relationship with Ana is a byproduct and not the cause of his transformation.
Now that Harold has changed and grown into his authentic self, learning to live and love, what does he do? He decides he should die for a greater cause--make his death meaningful. While this is uniquely Heideggerian and therefore very existential, it does not fit neatly into this particular thematic argument; therefore, I am going to pretend that it never happened.
.................................That sounded funny while it was still in my head..........Oh well.....................................
The truth is, it did happen. Harold diverged from the very force that had driven his transformation. His will to live became a willingness to die. But it was not because he had been conquered, submitting to Lord Eiffel's will. No. His compliance was due to the fact that he had seen the story; a story that could not exist unless he did not; a story that, in his mind, was so important and so beautiful that it had to be shared with the rest of the world. The old Harold couldn't have seen such things, blindly trudging through the tunnel of his automatous existence. The new Harold, however, could not only see the beauty, but felt a responsibility for its preservation, which, ironically, is what ends up saving his life.
So, let's see, Harold's will to live is the cause of his transformation. His transformation is what saves his life; thus, though circuitously, his will to live prevails.
I guess it fits after all.