The speaker reflects back to a particular moment in their life when they realised that the love had died between them and the person they were in a relationship with. They consider what this moment has meant to them since.
The four stanzas of the poem are all written from an individual first-person perspective. Given the subject matter, the reader might expect the speaker to be bitter and resentful about what had happened in the past but as the title highlights, the speaker seems to be almost neutral about the experience they're describing. Underneath the surface, however, a sense of loss and regret is hinted at, which perhaps suggests that love is something which is difficult to remain neutral about.
The imagery used is key to the reader’s understanding of the content of the poem and of the emotion (or apparent lack of emotion) behind it. Everything is described as lifeless and decaying and the vibrancy of nature has been replaced by an absence of colour – gray and white dominate.
The reader is left entirely alone to make up their mind about any reaction to the poem they might have. However, it is important to remember that the reader is dealing with only one side of the story - the speaker’s. We have no idea how the other person feels or what they think, so for the reader it is much harder to remain entirely neutral.