Your skin is your largest organ; a living part of you, although the bit that you spray with perfume is dead. A layer of dead cells that is constantly sloughing off and being replaced, which protects you from the outside and prevents most of the outside from getting inside. It is part of you, and each "you" is different. It has just been (re)discovered that the cocktails of chemicals in your breath is unique to you and a good indicator of your health, lifestyle and metabolism; so too is your skin a good indicator of your health, lifestyle and metabolism. Fragrances appear different on different people because of their health, lifestyle and metabolism.