In Greek mythology, Poseidon (Neptune) was ruler of the waters, oceans, and seas.  He was also ruler of dreams and the unknown.  In astrology, the planet Neptune represents all matters related to water, liquids, music, poetry, movies, glamour, dreams, and illusion. Neptune is the planet of the mystical.  It rules spirituality, ideals, hunches, and things we intuitively know.  Also included in it's domain are fog, flattery, fragrance, addiction, hypnosis, and hypochondria.  The location of Neptune in your birth chart will reveal where you are inspired and where your perception may be distorted. One could say, "Neptune rules all areas where we are enlightened through intuition, as well as all areas where reality is obscured by illusion." If you're not sure where Neptune falls in your birth chart, you can send me an email with your location, date, and time of birth (remember, I must have all three in order to provide the house placement). I would be happy to email that information to you.