Erich Fromm
Author: Erich Fromm
Publisher: Continuum Impacts (2005)

This miracle of sudden intimacy is often facilitated if it is combined with, or initiated by, sexual attraction and consummation.  However, this type of love is by it's very nature not lasting.  The two persons become well acquainted, their intimacy loses more and more its miraculous character, until their antagonism, their disappointments, their mutual boredom kill whatever is left of the initial excitement.  Yet, in the beginning they do not know all this: in fact, they take the intensity of the infatuation, this being 'crazy' about each other, for proof of the intensity of their love, while it may only prove the degree of their preceding loneliness.