..Anne's own analysis of her own behavior??

The next sentence says: "She had been forced into prudence in her youth, she learned romance as she grew older: the natural sequel of an unnatural beginning."

Therefore, the object of her affection did not change over the years. However, the reasons for her fixation changed. Or perhaps she grew to understand their relationship better. Yet at the same time she realized the futility of hanging on to a non-existent wisp of hope.

As for the spreadsheet, might a graph plotted over time suffice?