Our bodies before perfume, soaps, and any other added scents have their own natural aroma. This may be determined by your daily diet, hormones, and overall genetic composition making it subject to slight changes.
The same fragrance is bound to react differently with each user's chemical composition since you are combining the scent with your natural smell. However, the differences among users shouldn't be drastic but, ever so slight when pairing a new fragrance to your daily activities.