William Blake's "The Sick Rose" speaks of a rose, sick because of a worm, which is about to be destroyed. The rose, unaware of the worm, is joyous. Unfortunately, the rose is utterly unaware of the worm's presence.
The worm, therefore, is deadly. It is the worm which will leave the rose destroyed in its "bed of crimson joy." The rose, on the other hand, simply gives the worm something to "feed" upon. The rose provides sustenance for the worm.
Figuratively, the rose represents a literal rose and a figurative image of love. Literally, a worm will feed upon a rose. Figuratively, a worm illustrates the decay of love. As the worm feeds, the rose, "love," dies.
Therefore, one could state that one-sided love will never survive. It takes two people feeding love for it to survive.