In the third stanza, the speaker straight-up says that youth is the best time of life. This is partly because it is associated with life and health rather than death and sickness. Elsewhere in the poem, he celebrates the "prime" of one's life, the time when a person is most desirable for marriage (i.e., still young enough to look good and, perhaps, have children). In many ways, the poem says what all of us have always known: getting old is kind of a bummer.
- Line 1: The speaker tells the virgins to gather their "rosebuds" while they still can (i.e., while they're still ripe, not old or dying). By the end of the poem it becomes clear that rosebuds are probably a metaphor for marriage.
- Line 2: The speaker reminds the virgins that time ("Old time") is passing and that flowers may die soon. Time doesn't literally fly, so flight is a metaphor for the passage of time. While the flowers are a metaphor for marriage, they also seem to be a metaphor for human life, which can be just as fleeting.
- Line 4: We associate death with old age, and the speaker says that the flowers may die soon. The flowers are a metaphor for human life, which can end suddenly at any time, with no discernible reason.
- Lines 6-8: The sun's progress ("race") through sky is a metaphor for a human's journey through life. The farther along we get – the higher, in the metaphor – the closer we are to "setting," or death. The sun doesn't really "set" or "get" higher; this type of attribution of human qualities or actions to a non-human thing is called personification.
- Lines 9-10: The "first" period ("age") of our life is best, the speaker says. He clearly means youth, or the time when we are not cold (dead) but rather "warmer." The temperatures here are a metaphor for health, vigor, and youth. (One's temperature doesn't literally change over the course of one's life.)
- Lines 11-12: The speaker presents the process of aging as a gradual decline, where everything gets progressively worse. "Spent" (meaning "used up") is a metaphor for the loss of one's youth.
- Line 15: Old age is described as the loss of one's "prime" (i.e., the time when one is most active, most able to get married, etc.).