I once worked with a woman who told me and several other co-workers that she was having an affair. In fact, her love interest sometimes sent her flowers at work.

As if that weren't awkward enough, I coincidentally worked with her husband at my other part-time job. Although I didn't really know him, I knew who he was and I felt uncomfortable every time I passed him in the hallway.

I have no idea what ever became of their marriage. But almost 20 years later, I still remember how strange it was that this woman felt so comfortable sharing such inappropriate information with her co-workers.

Now, as a psychotherapist, I have a much better idea about why some people share too many details of their personal lives. Here are the five biggest reasons oversharers insist on spilling the beans:

1. False Sense of Intimacy

There's a reason why hairdressers hear intimate details of their clients' lives. When someone is touching you--cutting your hair or painting your toenails, for example--it creates a false sense of intimacy.

You might not even know the person's name, but that person is in your personal space, touching you. For many people, that physical touch gives them permission to start talking as if they were communicating with a close friend or partner.

2. Solace in a Stranger

Ever sat in a waiting room or on an airplane next to a stranger who insisted on giving you too many personal details of his life? Quite often, people tell complete strangers their deepest, darkest secrets.

A stranger won't judge you. And if he or she does, what does it matter? You won't see that person again. So for some people, unleashing embarrassing secrets and painful memories on an unsuspecting stranger seems like a less expensive alternative to therapy.

3. Misguided Attempt to Fast-Track the Relationship

When you meet someone new, whether it's the new office assistant or a blind date, there's a little tension as you start to negotiate your relationship. You have to look for clues to decipher if the person likes you or is interested in getting to know you better.

For many people, this initial phase is anxiety-provoking. So in an effort to skip over the "let's-get-to-know-each other" period, they start revealing problems about their bodily functions and strange phobias. They hope sharing such private details will fast-track the relationship to the next level.

4. Poor Boundaries

Sometimes, oversharers lack personal boundaries. They have no idea that it's inappropriate to tell co-workers about relationship issues or to reveal financial problems to total strangers.

People who lack boundaries sometimes lack close relationships--mostly likely because they've driven people away. So they often don't have close confidants who are interested in hearing about their personal issues.

5. A Hasty Effort to Make Someone Else Feel Comfortable

Whether someone reveals intimate relationship problems or childhood horror stories, an unsuspecting listener is put in an awkward place. Quite often, a caring listener will try to help the oversharer feel more comfortable by sharing personal details of her own.  

There are a few oversharers out there who recognize this and they disclose their tragic stories as a way to elicit sympathy--or perhaps even to gain intimate details of the other person's life. They're good at what they do, and they often manipulate private people into sharing a little too much information.

How to Respond to an Oversharer

If someone is giving you too much information, your first line of defense should be to change the subject. Try saying, "Sorry to hear that. Have you heard the weather for tomorrow?" Sometimes, they'll take the hint.

If the other person continues to overshare, you may need a more direct approach. Saying, "It's hard to maintain a professional relationship with you when I know so many details of your personal life," could be helpful.

And finally, don't reciprocate. Just because your boss tells you she's going through a divorce, it doesn't mean you need to tell her about your marital problems.

Sharing your personal story can be empowering. But only when you share it at the right time, in the right place, and with the right people.