Singular Focus/Obsession/Love

In terms of socialization, what is the difference between "Singular Focus," "Obsession," and "Love?" Seriously... How do we know the difference? And can either really be considered wrong? I hold a special someone in mind nearly every conceivable moment I can recall. Keep in mind that while we've both confessed a mutual love for one another, we are very far apart and can not truly be together at the moment. So perhaps it's simply the longing in the distance that keeps her there. Not to say that it isn't Love... That much, I assure you it is. I suppose that's just my way of claiming it isn't obsession, which I feel has a very negative connotation. Either way, really, I can't get her out of my thoughts... And I don't want to.

I'll keep waiting.