I recently received a phone call from a friend in need. She had done what she said she wouldn't do, what we all intend not to do -- spent the night with her ex.

It was, as they say, like a scene from a Hollywood movie. They ran into each other on the street, she ignored him, he chased after her, told her he was sorry, that he (of course) had changed. Moments later, they were back at his place rehashing the past.

After a year of swearing no one would ever hurt her again the way he did, within moments of seeing him it was too appealing to revisit the place where they were a couple and a time before he had broken her heart so callously.

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As I listened to my friend's story and wanted to wring her neck for letting this jerk back in her life, I couldn't help but relate to how easy it can be to let it happen.

He hurt her badly, and there were so many emotions tied up in it that it was hard to look the other way when he returned. Despite the pain, she wanted to believe he could be the person she thought he was.

While my friend said, "What happened, happened," and she has no thoughts of being with her ex again, I worry this fling, like so many others we have experienced, did more damage than good.

She may see the "one last time" as a way of finding closure, but there is no closure.

No matter how happy I am with someone else, no matter how far in the past that heartbreak was, I don't forget. I don't harp on the men who toyed with my heart, but those hurts are a part of me -- if only to remind me not to go back and show me how far I've come.

Ultimately, there is no satisfaction in a mishandled relationship, even when one ex came onto me and I flatly rejected him or when I announced my engagement and another said, "What?!"

Some would say I'm silly, that reconnecting in a physical way heals old wounds, that letting go with an old lover is not only beneficial but fun.

But as I see it, it only opens up new wounds. Some people, like my friend's ex, don't deserve to come back from the past. In fact, sometimes coming back from the past is just taking advantage of the dumpee's vulnerability.

I made that mistake once, and my ex only ended up more hurt than the first time I ended our relationship.

Not all exes represent pain. Those who don't are the ones who it isn't too detrimental to call when you need some attention. Sometimes it's just too easy to reconnect with an old flame. He knows you, you know him. There is a comfort level there.

Yet it's never quite the same, and maybe that's why I let that guy back in, even for a moment. Many times kissing the ex only drives home why I am not with him anymore. The lips that used to be appealing feel like mush. Somehow he just smells odd, and the jokes that used to work seem too tried.

So I know I have no more opportunities to reignite the sparks with any of my exes, but I hope my friend stays away from hers. It can be fun to revisit lips that used to make me crazy, but inevitably there is a reason they aren't around anymore.

People are capable of change, but making out in the street isn't the way to show it. Some bad apples aren't capable of ever cleaning up their act, a year later or ever, so keep them in the trash where you threw them.

Laura Lewis is an adventurous 20-something who knows how to make the most of being single. Her column appears every other Thursday.