Shall these trees stand forever?
and the fields,
brown, green, gold, according to the season,
shall they remain?
But the hills,
they shall be there.
No not even those.
What then shall stay?
Their having been is what shall be left.
And when you are gone,
and I am no longer here,
we too shall have been,
and nothing can be quite the same again.
The title does not mean that the future will be perfect - it is an unusual tense, speaking of a future where what we know now will not exist. It was a long time before I realised "we too shall have been" could sound like "we two shall have been," but that was not my intention, and it would suggest a different story.