oh i see what you mean...
its simple, i dont know much about it tho but i can kind of guess at it
depending on what goes into your body whats in your environment etc, your skin will be different, and or your body will compliment certain cologne notes differently. for instance if you eat a lot of fat or if your skin is really oily the cologne will bond to those oils, somewhat changing the scent a little and making it last a lot longer on your skin. if you have dry skin the cologne will dry down faster, scents will break down and the cologne will smell different. how acidic your body is, sweat, tons of other stuff will effect certain notes and change the cologne from person to person
some people cant do the fresher scents, they dry off the skin too fast and break down easily, making it seem like some cheap cologne, almost like you might as well have used some fresh scent deodorant. other people will have the fresh scent stick to them all day long as a pleasant trace ppl cant get enough of. some people cant do deeper muskier scents because of the same reasons, it will break down fast and smell cheap and too musky, other people it will stick and create a deeper more intoxicating aroma. you just have to figure out waht works for you by spraying it on you and smelling it. create a large collection so you can alternate colognes as your body chemistry changes
so maybe a strong top note that compliments someone very nicely, like for instance bergamot is a top note in aqua di gio, will be broken down and changed by someone else, and at the same time a base note like patchouli will be intensified.
one person with intensified bergamot top note and broken down patchouli note, and another person with broken down bergamot note and intensified patchouli = two different scents. also maybe one person sprayed the cologne directly onto their skin and rubbed it in, and another person misted it into the air and let it fall onto their clothes. = two different scents
