Sonnet 55 - Reflection

Sonnet 55 is a love poem, as are most sonnets, but this one doesn't seem as hard to dissect. This poem clearly stares "You live in this, and dwell in lovers' eyes". I want to comment on the validity of that statement. I believe that the speaker really meant that about the boy. This young man will live on forever in a literal and hypothetical way. These poems are in writing; they can be kept and taken care of and eventually translated. While I understand the meaning of it I am curious about why this boy needs to hear these words. You'll live on and no one can stop you through the letters of a poem. Memorials and monuments may fade but only a poem will live on. Why was the speaker so insistent on him living on? Aren't the parents insisting that it will happen through a child? Does the speaker believe that the young man wants/will have children or is this, the poem, where he stops? Does the boy only last through the poems?