On a smaller, narrower level, there might be unreturned love. In the grander scheme of things, there is more than enough to go around. It's just a matter of being attuned to it. Of 'being able to see the forest through the trees.'

This poem goes well with Whitman's Salut au Monde.

Sometimes With One I Love

Sometimes with one I love I fill myself with rage for fear I
effuse unreturn'd love,
But now I think there is no unreturn'd love, the pay is
certain one way or another,
(I loved a certain person ardently and my love was not
return'd,
Yet out of that I have written these songs.)

-Walt Whitman