You can read this poem at the Poetry Foundation here.
How can you add anything to Keats? The knowledge of how short a time he lived adds an almost unbearable poignancy to this poem. That final image is so beautiful and resonant: it captures not only how the immediacy of grief isolates—in grief, we are all ‘on the shore/ of the wide world [standing] alone’—but also how encounters with mortality make everything else look different, fall away… We are all writ on water, and to see that can (as our Philip puts it in ‘Aubade’) ‘hold and horrify’.
But of course, the very existence of this poem is testimony to the fact that we do not have to stay paralysed by the realisation of our own finiteness. It we grieve it, maybe we’ll be able to respond creatively. As Keats did.