W.H. Auden, "September 1, 1939" - one of my favorites. Read the whole thing
here.
A few choice selections:
Faces along the bar
Cling to their average day:
The lights must never go out,
The music must always play,
All the conventions conspire
To make this fort assume
The furniture of home;
Lest we should see where we are,
Lost in a haunted wood,
Children afraid of the night
Who have never been happy or good.
...
For the error bred in the bone
Of each woman and each man
Craves what it cannot have,
Not universal love
But to be loved alone.
...
We must love one another or die.
Auden actually went back and edited the poem late in laugh, and made it considerably darker. He changed that last line to "We must love one another and die." which is so heartbreakingly perfect.