I HAD this thought a while ago,
'My darling cannot understand
What I have done, or what would do
In this blind bitter land.'
And I grew weary of the sun
Until my thoughts cleared up again,
Remembering that the best I have done
Was done to make it plain;
That every year I have cried, 'At length
My darling understands it all,
Because I have come into my strength,
And words obey my call';
That had she done so who can say
What would have shaken from the sieve?
I might have thrown poor words away
And been content to live.

William Butler Yeats

http://www.poemhunter.com/poem/words-4/