"Yes and when the warm unseasonable weather / Comes at the year’s end of the next late year"
Although a seemingly simple construction, these lines set the complex tone for the poem and place the reader in a somewhat imaginative state of mind. Firstly, by beginning with the words "Yes and," MacLeish establishes a sense of certitude and confidence around the speaker. This diction also sets up the poem as if it's starting in the middle of a conversation. MacLeish's conversational choice gives the reader the impression that the speaker is engaging deeply with someone, sharing far-away thoughts and ruminating on life's movements. The rest of the lines serve to set up suspense, as the reader wonders what the speaker is so certain about that he is predicting the weather far in advance. Later in the poem, his certainty develops more meaning, as we discover what he's really certain about are the conditions of life we all must face.
"You will not understand why suddenly sweetness / Fills in your heart nor the tears come to your eyes:"
Perhaps the most beautiful, heartrending part of the poem, these lines evoke the universal human experience of being deeply moved—by a sound, a smell, an image or a memory–and not knowing exactly why. As the poem progresses, it becomes clear that this particular experience is nostalgia, and that the speaker is referring to someone moved by a distant memory. The juxtaposition of "sweetness" with "tears" illustrates the complexity of such an emotion, which often elicits feelings of love and gratitude, as well as loss and bewilderment.
"You will close your eyes: With whom, you will say, / Ah where?"
These poignant lines demonstrate the human capacity for curiosity and our desire to understand ourselves at the same time that we desire to forget. The phrase "You will close your eyes," indicates a moving effort to reach back into one's memory, as does the expression "ah," which suggests that one is concentrating or moved deeply. Also touching for the reader is that the speaker predicts the subject will say "Ah where?" out loud, which shows that the emotion around the faint memory is so intense that it moves a person in solitude to speak.
