Almost everyone has had the experience of smelling something in the air and being vividly reminded of another time or place where that particular odor was present. This “associative” or evocative nature of fragrance has its roots in the structure of the human body itself. The sense of smell differs from the other major senses in that it is more primitive, working more directly with that part of the brain, which is “older” in an evolutionary sense, than the rest of the brain.