Anything that has no desires is a non-entity.
One can desire something even while that desire is being fulfilled: for example, as I chew a piece of tart, sweet apple, I desire that flavor and tactile sensation even through this desire is being fulfilled.
One can have some unfulfilled desires and still be happy. I might like to climb Everest to the summit, but that doesn't mean that unless and until I do so I am doomed to unhappiness.
What determines happiness and unhappiness is the presence or absence of pleasant and unpleasant conditions. The exact kind, degree, and mixture of such conditions will determine the relative happiness or unhappiness of the individual, according to that individual's intrinsic nature. The further away an individual is from his natural state, the less happy he will be. By "natural state" I do not refer to some atavistic state, but rather to the set of circumstances conducive to happiness for a particular individual at a particular time in that individual's development, as well as to the progression of that development (personal change) along natural lines. To the extent that one's environment and/or personal development (and the former generally influences the latter) deviate from the natural state, that individual will be less happy than he would otherwise be; and if the deviation is sufficient, he will be unhappy, and more unhappy the greater the deviation is.
This does not imply, for example, that the natural state of serial killers is committing horrible, wanton murders. That is nobody's natural state. However, the odd behaviors misattributed to human wickedness are in fact merely the behaviors of pseudo-sentient, defective imitations. Nothing in the appearance or "history" of the world should be taken at face value, since there is no reality behind it. I occupy my own universe and I am the sole inhabitant there. My universe consists solely of sensory experiences of the type I refer to as "external". Those sensory experiences are figments. Mechanical causality is a fraud in my universe, since the figments cannot and do not interact by means of it, being figments.