Real spiritual love, love of God and love of mankind for the sake of God is the only truth, the only thing in this world that is permanently and constantly sweet. Physical separation from someone you love, in accordance with the rule that pertains to the physical, may create a longing that will cause love to increase, may augment the bliss of reunion. But on the spiritual level that love is constant, is never interrupted by distance nor by time. Your beloved may be on the moon and you may be in bliss at the thought of reunion, but if love is unrequited, that is not sweet separation but a bitter pill. The extinction of love is pitch darkness.
Love is the water of life.
God created Adam from clay and water. If it were not for water the clay would hold no shape. Divine Love is what binds our souls together. That is why people become so miserable when they feel unloved. It is a feeling that something essential is missing from one's life, that life itself is incomplete, and in the face of this ache people set out in search of love with the desperation of a man dying of thirst.