Unrealistic expectations can set your relationship up to fail. But there are so many false relationship rules floating around out there -- that girls should never call guys first, that men should always pay for dates -- it's hard to know what you should believe.

"Many people grow up believing the Hollywood version of love, but just because something is in a movie doesn't mean it's true," says Joel Block, PhD, a couples therapist and co-author of "Sex Comes First: 15 Ways to Help Your Relationship -- Without Leaving the Bedroom."

So, we asked him to weigh in on some of the most popular relationship myths and give us the real story.

10 Relationship Myths Debunked

    The Myth: Your rebound relationship could really last
    The Truth: Sure, and Paris Hilton could win an Oscar. You need time to heal after a relationship and if you jump into another commitment, you probably won't be in the headspace to make it last long term.

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    The Myth: You should love each other equally
    The Truth: Love isn't easily measured, but most strong relationships have one person who is more accommodating and doting than the other person.

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    The Myth: All men fear commitment
    The Truth: Plenty of men yearn to be in long-term relationships. Even commitment-phobes aren't actually fearing being in a relationship, they're just nervous about losing some of their freedom.

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    The Myth: You should always agree
    The Truth: Can you imagine how boring it would be if you and your partner were always on the same page. What really makes for a successful pairing is when you can disagree and still respect where the other person is coming from.

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    The Myth: Grand romantic gestures are crucial to making love work
    The Truth: Carriage rides and fancy surprise dinners aren't what keep your bond strong. Instead, everyday gestures- picking up each other's favorite ice cream or texting to say "I love u"- are the true signs of lasting love.

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    The Myth: Opposites Attract
    The Truth: Sure, someone that is wildly different may intrigue you, but it doesn't work in the long run. If you're extremely different, you'll constantly be frustrated and butting heads.

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    The Myth: Love can get you through anything
    The Truth: Hardly. You can love some one deeply, but some problems- addictions, terrible family members, etc.- are just too big to overcome.

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    The Myth: You should know everything about each other
    The Truth: You should know a lot about your partner, but some mystery will keep things fresh. So, there's really know need to share how many guys you've slept with or what your waxing schedule is.

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    The Myth: You should feel "in love" with your partner every second
    The Truth: Those feelings of strong, undying love ebb and flow in any relationship. It's totally natural to want to occasionally wring your partner's neck.

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    The Myth: Love at first sight exists
    The Truth: You may be attracted to someone right off the bat, but you definitely can't know you love someone just by looking at him or her. Those feelings tell a little more time to build and require having conversations.

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