In my childhood, while travelling in a train, I used observe an interesting phenomenon. When the train stopped at a station and another train would pass by it, it seemed as though the train I was in was also moving. As soon as the other train passed, it became obvious it was just an optical illusion and that my train was still stationary.
In this same way, the conditioned soul, wrapped in the bodily conception of life, thinks of his self as moving and ever-changing, although the soul as he is does not change at all. It is only by identifying with the body and thus with the senses (through pro-longed lustful sense gratification) one becomes illusioned to think he is one with the body and thus with the material world, although in actuality he is completely aloof. Lord Krishna explains in the Bhagavad-gita that the souls is taking newer and newer bodies just as a person is putting on clothes daily. The gross and subtle covering consisting of the earth, water, fire, air, either, mind, intelligence and false ego can be compared to the inner and outer covering of a well-dressed person. As it would be foolish to address ourselves as Mr. Black Sweater or Mrs. Red Skirt, similarly it is a sign of insanity to address and think of ourselves as men, women, animals, plants, ugly, beautiful, rich or poor.
It would be also foolish to conclude that after a person undresses he becomes zero. Some philosophers claim that after suffering in the world of false designation one should artificially think that the self is a mere concept, which we should simply annihilate in our mind through the process of concocted meditation on nothingness and thus commit spiritual suicide. Such frustration-based philosophies have been torturing the men of this world since time immemorial and one should carefully avoid such nihilistic desperation. It is only after undressing people experience intimacy when engaged in sex life. Similarly, it is only after liberation one can experience the intimacy of spiritual life (that is completely opposite in nature to mundane sex life) with Krishna. Such intimacy can take place in multitude types of rasas (mellows of love) in one's original swarupa or form. One should therefore carefully avoid both false identification with the material designations and attachment to the designationless senseless nonsense conception of the soul. Both have been tormenting the spirit soul since time immemorial.