Even in detachment there is a background promise of happiness and this translates as the future prospect of possessing the power to gratify desire. That's a long chain of mediations but it's strong enough to transmit some energy. And what is at the end of it but a scene of your own gratification? If you envy others when you see them experiencing such joy, desire is the same process applied to yourself in the form of an imagined future self. So desire is envy of yourself. Many directed emotions, positive or negative, have a reflexive form, there is self-love, self-respect, self-esteem as well as self-hate, self-contempt and indifference to self. Self-envy seems impossible, but this is only so if the self to be envied is located at the identical point of time. Desire is thus envy of a future self. Strong desire, like envy, hits you in the pit of the stomach, blanches your features, and it prompts scheming, rehearsals and fantasies, and the shocking sense of a sudden rearrangement of powers. This is the reverse of the idea that desire prompts imaginary or even hallucinated scenes of gratification - no, these images come first and desire is the response, a secondary, even defensive reflex. Still this is not the end; it suggests that there is a sort of proto-desire, an undirected, unformed disposition to respond with desire - a pure indigence, a nothingness at the heart of being.