"Longing is not always oriented toward the future. It can as easily be retrospective. You can long for what you have already experienced. Sexual fantasies, for example, are memories (sometimes slightly improved on) as often as they are inventions, albeit memories that are in danger of fading even as they are summoned.
Nor is longing always person- or object-specific. You can be in a state of generalized longing without knowing quite what it is that you long for. This might be the purest form of longing, the most difficult to assuage, the least susceptible to being brought to an end, the kind capable of lasting longest—so much so that it can become all but indistinguishable from a generalized condition of existence..."
Text By Geoff Dyer | The Paris Review