Heartbreak
The speaker's recent heartbreak, brought on by the end of a relationship, causes the world as a whole to feel unrelentingly bleak. An interesting aspect of this poem's approach to the theme of romantic heartbreak is the way that the speaker still experiences a feeling of solidarity with her former lover. She often uses the second-person and first-person plural pronouns, grouping herself and her ex-lover together. They are both alone, but are united in their loneliness. However, this only serves to make the speaker's loneliness feel more intense and intractable.
The Passage of Time
One of the speaker's central preoccupations is the way that time seems to move forward almost aggressively, which both makes it impossible to reverse one's past actions and makes moments of joy short-lived. The poem begins with a reference to turning the clocks back in the fall. This ritual functions on a literal level, but it also symbolizes the cruel progression of time, and the way that time seems to "steal" the speaker's happiness. The poem's title holds multiple meanings, including the possible reading that time is mean in the sense that it is unkind or malicious. The speaker, in a moment of sorrow and loneliness, certainly seems to feel that time is treating her with malicious intent.
Regret
One of the reasons that the speaker so resents the passage of time is her sense that her mistakes and regrets are irreversible, entrenched by the way time moves forward. She feels no defensiveness about her mistakes, and does not appear to feel especially angry about the regrettable ways in which her lover hurt her. Instead, she is haunted by the knowledge that these hurtful choices cannot be taken back, even if both parties wish that they could be. The speaker describes the almost physical pain of feeling her heart "gnaw/at all our mistakes," as if the awareness of these mistakes is prompting a kind of spiritual decay and discomfort. She feels that, if time offered more generosity and flexibility, she might be able to reverse both the regrettable things she has said and the regrettable things said to her.
