In the second quatrain, Shakespeare speeds up the entire course of a human life to fit in a day. This is to suit his metaphor of life as the rising sun, but the timelapse also shows that life itself is as short as a day. It begins to descend as soon as it peaks, its radiant beauty now marred by “crooked eclipses” (Line 7). The greatest irony of short-lived life is that its peak—youth—is even briefer. In the third quatrain, the poet notes that the lush extravagance of beauty is easily marred by rows of wrinkles planted by time. Time is depicted as a cruel, vampire-like force feeding on beauty and truth. All these examples illustrate the theme of the impermanence of life, especially youth and beauty. The poet is always acutely aware that human minutes are ephemeral and fragile, an idea reinforced through the images of waves breaking on the rocky shore in the first stanza.

Even when the poet describes the glorious parts of life—nativity and youth—the accompanying vocabulary is conflicted, indicating his awareness that the glory is impermanent. For instance, he notes that “nativity, once in the main of light, / crawls to maturity”(Lines 5-6). Infancy, the expanse of light, is already ended, as denoted by “once” (Line 5).