I will not give thee all my heart
For that I need a place apart
To dream my dreams in, and I know
Few sheltered ways for dreams to go:
But when I shut the door upon
Some secret wonder-still, withdrawn-
Why does thou love me even more,
And hold me closer than before?
When I of love demand the least,
Thou biddest him to fire and feast:
When I am hungry and would eat,
There is no bread, though crusts were sweet.
If I with manna may be fed,
Shall I go all uncomforted?
Nay! Howsoever dear thou art,
I will not give thee all my heart.

Grace Hazard Conkling

http://www.poemhunter.com/poem/i-will-not-give-thee-all-my-heart/