Answer: This is the way we are built; these are our desires. We can fulfill them only through the means that have been given to us: hands, legs, the five senses, and the brain.
My calculation is rather simple: to fulfill myself as much as possible with the desired pleasures and constantly to remain fulfilled 100% of the time. But the moment that I approach the upper line of fulfillment, the pleasure disappears, and I need to descend a little. For example, before a meal, I must be hungry in order for it to give me pleasure.
We need to be concerned to create the Kli (vessel) and the fulfillment that is suited to it. Nevertheless, the fulfillment doesn’t need to extinguish the deficiency, but rather to accompany it. It is best when the fulfillment and the deficiency go hand in hand; the more I receive, the more I want; I still receive and I still desire, again and again.
Here the question arises: What do I feel—eternal pleasure or eternal deficiency, or maybe once this way and once that?
In our world the only possibility to enjoy both the deficiency and the fulfillment is if they are directed to a third party. Then both of them are desirable and exist within me. Not alternately, but at the same time, together. About this it is said, “Love covers all transgressions.”
If they exist side by side, then from within their combination the middle line is created, and I constantly enjoy myself, without end, without any transition between the deficiency and the fulfillment. And thus I reach the form of Infinity, and I don’t need to replace the periods of deficiency and fulfillment.
From the 4th part of the Daily Kabbalah Lesson 2/6/12, “Introduction to the Study of the Ten Sefirot”