The underlying theme of Western poetry is mortality. The theme of carpe diem asks us to seize the day because we have only a limited number of them. To see life through the lens of death is to approach the condition of gratitude for the gift (or simply the fact) of our existence. And as Wallace Stevens said, Death is the mother of beauty. Only the perishable can be beautiful, which is why we are unmoved by artificial flowers.
Interview with Kritya: In the Name of Poetry