The ache of desire is real even if the object of obsession is unreal, or only partially real. It's absurd. One of the hallmarks of obsession is that you burn to possess something but don't even know what you mean by that. When choosing among various falsehoods competing for your heart's attention, pick the one with the sexiest thighs. The target, by his very existence, fills a need you didn't know you had until he aggressively shoulders his way into your thoughts, in fact becomes your thoughts, by using the seductive technique of casually talking to you or noticing you at all. This need, which didn't seem to exist before, then becomes a howling void if left unfulfilled. You see him only through an unsilvered mirror, his face and your reflection, each accentuating the unreality of the other.