Your nose contain thousands of olfactory nerves. While your tongue has the ability to taste sweet, sour, salt, and bitter, it is your sense of smell that creates all the delightful flavors you experience. The olfactory bulb is part of your brain's limbic system, which is not under conscious control. The limbic system controls digestion, libido, and emotions. So, it's not your imagination that scents evoke emotion.
Aromas actually trigger the release of chemicals in the brain that create a feeling of well-being.
Scientists say your body's response to an aroma takes just four seconds. Essential oils are available in natural and synthetic forms. Pure, natural essential oils may be as much as 70 times more potent than the plant source itself. Some synthetics are derived from natural products. The exact formulation of an essential oil is virtually impossible to reproduce in the laboratory.