Like the sun that shines brightly at noon but fades at evening, you have limited time to shine and produce heirs.
Sonnet 7's extended metaphor of the sun's daily arc brilliantly captures youth's trajectory: rising, peaking at noon, fading at dusk. The sun commands worship at morning and noon but is abandoned at sunset. This mirrors how the world honors beauty in its prime but turns away from age. The implicit warning: your power to attract and influence is temporary; use it now to secure immortality through an heir.
The sonnet measures value by the gaze of others: eyes follow the sun at dawn and noon, then abandon it at dusk. Without children, the youth will experience this abandonment—all eyes turning away as beauty fades. But a son would ensure that people still see the youth's beauty in his face, maintaining the gaze even after the original fades. Legacy is thus redefined as the continuation of attention.
Your career peak is in your 30s; you have limited years of maximum influence to shape the next generation. After that, you're in the 'decline' phase.