Why am I only attracted to unattainable guys? As soon as men express interest in me, I lose interest in them. How do I break this cycle?! 

--Frustrated

At the moment, the perfect love poem for you would come from a clerk at the court: "Roses are red, violets are blue; stay 500 feet away, or it's handcuffs for you!"

Chances are you're looking to win, not looking for love. Once you win -- once you've landed the guy you've been pursuing -- you're done. However, you probably tell yourself you're seeking romantic connection because, well, it's more appealing than admitting you're the human version of a dog chasing a dirty tennis ball. The point -- the excitement of it -- is the chasing, not the getting. (Dirty tennis balls don't taste like bacon.)

You're basically on an emotional crack bender. The big neurochemical player here is dopamine, a neurotransmitter, a messenger in chemical form that carries signals from brain cell to brain cell. Though it's often called the "pleasure chemical," that's wrong. Giving you a buzz is opioids' department. Getting you to the opioids is dopamine's job. Research by neuroscientist Kent Berridge suggests dopamine drives "wanting" (as in, craving) -- motivating you to pursue things that are "rewarding," like sex, drugs, and cake.

There are some nuances to this. Dopamine is the Beverly Hills brat of neurochemicals -- seriously snobby about rewards being new. In researcher-ese, it spikes at the prospect of "novel rewards": sex, drugs, and cake you haven't tried before. It also goes up big-time for "unpredictable rewards" -- those we aren't sure we can get -- which explains the allure of the seemingly aloof himbo. However, "predictable rewards," like the Grandma-pleaser -- the nice, stable fellow you can always count on -- read as a big "meh" in Dopamineville.

I'm guessing your love of the chase has a second job -- as convenient cover for repairs needed in your emotional wing. Get to work on your self-worth, self-acceptance, and any other self-(s) in need of shoring up. While you're an emotional work in progress, be honest with men you date that you have a tendency to disappear like cartoon ink. Eventually, however, your efforts should be transformative -- meaning the meme guiding your romantic life will no longer be "Look for a man who looks at you like my dog looks at the small print on the iTunes agreement."

For pages and pages of "science-help" from me, buy my latest book, "Unf*ckology: A Field Guide to Living with Guts and Confidence." It lays out the PROCESS of transforming to live w/confidence.