Sigmund Freud gave fantasy a bad name back in 1908 when he said, "A happy person never fantasizes, only a dissatisfied one." Granted, this is also the guy who said clitoral orgasms were immature, and fortunately, we've had a century of research (and impassioned women) to prove Freud wrong.
The truth is, a healthy fantasy life is one key to a great sex life--and your partner might not always play the leading role. Fantasy isn't the sad daydreaming of the lonely, forlorn or frustrated in love. Research shows that people with active fantasy lives are more sexually satisfied, more sexually responsive and more adventurous about sex in general. Not bad.