Desire (OED): that feeling or emotion which is directed to the attainment or possession of some object from which pleasure or satisfaction is expected; longing, craving; a particular instance of this feeling, a wish
Desire is a basic fact of the modern ego. Popular culture proclaims you can have anything you want to have or be anything you want to be if you only want it enough.
One of the catches is that, within the modern Romantic framework, you can only want what you cannot have. If you have something, then it is real and present and cannot be yearned for. Therefore, no matter how a child's parents may provide, the child cannot want what they provide but only what they do not provide.
is structured yearning. In the romantic
moment, we gather and focus that yearning in order to connect with something
outside ourselves, believing against all odds that such connection is possible,
knowing paradoxically that romance is born in the space between our
reach and our grasp. "
"Barbara LazearAshcher, Dancing in the Dark: Romance, Yearning, and the Search for the Sublime. NY: Cliff Street, 1999, p. xiii.
Loss (OED: 2. The fact of losing [something specified or contextually implied]. . . . 2a. The being deprived of, or the failure to keep [a possession, right, quality, or the like]) comes into play when an object of desire is gained, as in Poe where the narrator wins the love of his life and faces the danger that the longed-for desire becomes present and real and thereby undesirable. (Folk example: the dog who chases cars; if the car stops, the dog doesn't know what to do with it.)
If, however, the desire object is then lost (through death, capture, etc.), the fresh absence of love or fulfillment revives desire and the cycle of desire and loss continues, as at the end of Poe's Ligeia.