Analysis of Sonnet 74

Poems can be rather confusing unless there is some sort of an interpretation, the first two poems I can help clarify if needed but I figured "shakespeares-sonnets.com" could help me out with Sonnet 74.

This is the last of the quartet of sonnets which deals with old age and death. Finally the possibility of survival assumes a spiritual dimension. The fact that Time with his crooked knife can take all away is somehow alleviated by the persistence of the 'better part of me' which triumphs over the body's death. The poem links to many others in the series, especially those which deal with the unity of lovers, for here the poet's spirit is also the beloved's, and his spirit manifests itself in his verse, which will be a monument and a memorial for all time. Thus the miracle is achieved, that the dull substance of his flesh, no more worthy than the coward conquest of a wretch's knife, becomes transformed into the magic of eternal verse which conquers death and allows love to flourish where it seemed to be destroyed by death.