Whether you have a deep, rich sex life or have barely gotten started there's one erogenous zone you probably don't give much thought or attention to. And whether you're a man or a woman, your partner won't be stroking this delicate area anytime soon - at least not literally. That's because your biggest turn-on center isn't below your belt, or under your hair or in the crook of your arm, it's between your ears. Yup, your hidden erogenous zone is your mind, and all its sexual thoughts and fantasies. In fact, it's pretty much the Grand Poobah of erogenous zones. Too bad so many people give it so little attention.

After all, for many people sexual fantasy is in some ways more taboo than sex itself. Although the majority of people have sexual fantasies ranging from seducing a celebrity crush to getting publicly gang banged, many have difficult owning up to them. They feel embarrassed or afraid that admitting certain private desires could label them as deviant, slutty, or unhappy in their relationship.

But hey, people also used to believe that masturbating would make you go blind. Fortunately, we have science to rescue us from such things. As it turns out, sexual fantasy is a natural and even important factor in a healthy sex life. Here are a few of the things fantasy can do. (For a great, in-depth read on the topic, check out Arousal: The Secret Logic of Sexual Fantasies.)

Oh, Those Burning Flames of Passion

We all know that in order to have good sex, it’s important to keep in shape and be well attuned to our bodies' needs. The mind works much the same way. Scientists at the University of Granada in the Department of Personality, Evaluation and Psychological Treatment conducted a study in 2007 that indicated that inhibited sexual desire may be traced to a lack of a positive attitude toward sex (erotiphilia) and a low number of sexual fantasies. In other words, if you think sexy thoughts, it might mean enjoying a sexier life.

Another study conducted at the University of Michigan and published in the Journal of Sexual Medicine in 2012 measured states of arousal in men and women while they imagined a fantasy, read an erotic story, or performed a neutral exercise. Not surprisingly, the first three groups reported higher levels of desire, both below the belt and upstairs.

Sharing With Your Partner

Fantasies are made to be shared and if you're in a long-term relationship, it's important to spill the beans ... at least a little. This can either be done verbally, or ramped up through role-playing. Who knows? Maybe that dirty little fantasy you were afraid to tell anyone about is a personal favorite of your partner’s too!

Over time, most couples tend to lose that sense of sexual excitement that often helps bring them together. Bringing fantasy into the picture can be a great way to revive spontaneity and bring you closer together. After all, giving up a long held-secret isn't easy; it requires intimacy and trust which, incidentally, is what great sex is all about. Plus, humans crave novelty. Exploring new fantasies can be a great way to satisfy that need without sacrificing your relationship. (Read how one woman brought fantasy to her relationship in My Night With a Stranger.)

When Dreams Come True

So let's suppose that you and your partner bare all all those sexy secrets. Now what? Well, now it's time to choose a fantasy you're both comfortable with and give it a whirl. A few suggestions for acting out sexual fantasies: First, consider starting with the classics. A sexy schoolgirl outfit or just a simple blindfold can go a long way to opening up the doors to bigger, kinkier fantasies. And if you aren't quite ready to tell your partner about your big, bad, sexy fantasy quite yet, do indulge in it a little yourself. (A lot - and we mean a lot - of you are into bondage. Want to give it a shot? Check out Why Bondage Can Be So Much Fun.)

Fantasy or Reality?

One real hangup people get about fantasies is obsessing about what they mean. If I want to be tied up does that mean I'm submissive? If I daydream about other people does that mean I'm unsatisfied with my partner? If someone of the same sex pops into the picture, does that make me gay?

The answer is probably not. Here's a great example: According to a study by Mark Schwartz and William Masters published in the American Journal of Psychiatry back in 1984, "forced encounters" was found to be one of the most popular fantasies among men and women, both gay and straight. And that was wayyy before "Fifty Shades of Grey" introduced the idea of being tied up, spanked and sexed to within a few inches of your life. So, does this mean that people have some deep-seated desire for sexual violence? Far from it. In fact, the researchers concluded that rape fantasies were highly idealized to the point where they could barely be linked to the word, leaving one researcher to conclude that they were largely symbolic, especially for women. By being forced into sex, these fantasies allowed women to ditch the guilt around desire and enjoy the act. (If you think fantasies themselves are sick, chew on that for awhile.)

In the same vein, fantasizing about a threesome with your partner doesn’t always mean that either of your will want to go through with the real deal. If you do and that works for your partner, great. But keep in mind that a fantasy threesome can be a highly idealized version of what actually goes down. In this case, dreaming - rather than doing - means there's no jealousy, no risk and no one gets hurt. When you and your partner share fantasies, it's important to understand that fantasy doesn't always mean reality - at least not if you don't want it to. In many cases, it just means a little imaginative sexual play.

So ... What's On Your Mind?

Don’t think you have any fantasies? Or maybe you're just too afraid to admit that you do? Relax. It isn't a crime to not have a dirty mind. But if your mind does go there, allow it explore a little. Sexual fantasy is about getting to know who you are sexually, figuring out what situations turn you on the most, and generally discovering your sexual needs.

The best way to figure out what hits your sweet spot is a little self love. Relax, romance yourself, and read a dirty book or watch a sexy movie. Then, let your mind drift until ... until that one last thought pushes you right over the edge. That’s it. That’s your fantasy. It isn't bad or twisted or gross. It's you. So own it. Explore it. And if you want to, share it with someone you love. Who's judging? Even if someone does point the finger of shame at you, just remember that they probably have a fantasy of their own they’re too scared to admit.