I HAVE reached a curious point in life. Although I feel like the same precocious know-it-all cynic I always was, I suddenly am surrounded by younger precocious know-it-all cynics whose main purpose appears to be to remind me that I've lost my edge.

Many of these people are teenagers.

Some of them I gave birth to.

One was in a breech position.

And the other day, as I drove home with one of my tormenters in the passenger seat, she started laughing at the way I pronounced ''Henri Cartier-Bresson.''

''Ha ha ha, is that how you think his name sounds?'' my daughter said. ''Oh, my God. Who told you that?''

It was my college photography professor. Twenty-six years ago.

Rather than draw attention to my age, I tried to trick her into thinking of me as someone cool, as we said 26 years ago. ''I hope you don't think this gives you the right to make fun of me on your Facebook page,'' I said.

''My Facebook page?'' this person asked incredulously. ''My page? Is that what you think Facebook is?''

Suddenly a vague memory from my childhood -- the time someone else's mother left her family, wrote a few young adult novels and ended up in a sad apartment complex on the edge of town -- welled up, unbidden.

I needed to banish it, along with all evidence of this humiliating conversation. But how?

I vowed to fight on her turf.

So last week I joined Facebook, the social network for students that opened its doors last fall to anyone with an e-mail address. The decision not only doubled its active membership to 24 million (more than 50 percent of whom are not students), but it also made it possible for parents like me to peek at our children in their online lair.

At Facebook.com, I eyed the home page (''Everyone can join'') with suspicion. I doubted Facebook's sincerity. What could a site created by a student who was born three years after I started mispronouncing ''Henri Cartier-Bresson'' want with me?

Realizing that these were cynical, mocking thoughts cheered me -- I felt edgier already -- and gave me the courage to join.

After I got my Profile page, the first thing I did was to search for other members -- my daughter and her friends -- to ask them to be my friends.

Shockingly, quite a few of them -- the friends, not the daughter -- accepted my invitation and gave me access to their Profiles, including their interests, hobbies, school affiliations and in some cases, physical whereabouts.

Meanwhile, my Profile had News Feed to inform me of every development:

Michelle and Paige Ogden are now friends.

Michelle is out for a run.

Michelle and Jesse Bendit are now friends.

Michelle is home.

No word from my daughter, though.

Out of the blue, I got an invitation to be a friend from one of my neighbors, Ted, who coincidentally had just joined to check out the applications that independent software developers started adding to the site last month. He showed me how to add movie reviews and snippets of music to my Profile.

I invited my friends -- my actual friends -- to join Facebook. Some did. I sent a ''poke'' to one to say hello. I wrote on another's ''wall.'' I tagged a photo to make it appear on my friend Tina's Profile. In gratitude, she ''poked'' me.

Things were going really well, when suddenly something disturbing happened. An instant-message window appeared onscreen to deliver a verdict.

''wayyy creepy,'' it said. ''why did you make one!''

Ah, there she was.

''What are you talking about?'' I typed innocently.

''im only telling you for your own good,'' my daughter typed.

''Be my friend,'' I typed.

''You won't get away with this,'' she typed. ''everyone in the whole world thinks its super creepy when adults have facebooks.''

''Have facebooks? Is that what you think a Profile page is called?'' I typed.

She disconnected.

Feeling as if I had achieved a minor victory in the name of parents of teenagers everywhere, I phoned Michael Wesch, an assistant professor of cultural anthropology at Kansas State University whose research focuses on social networks, to offer him some real-life data to work with.

But although he didn't go so far as to say he disapproved of my parenting skills, Professor Wesch reminded me that what Facebook's younger users really are doing is exploring their identities, which they may not want to parade in front of their parents.

''Can't I explore my identity, too?'' I asked. ''Why does everything fun have to be for them?''

He pointed out that there are a number of other social networks -- sober, grown-up places like Linkedin.com (for making business contacts) and Care2.com (for social activists) and Webbiographies.com (for amateur genealogists) -- where I could cavort without offending my daughter.

''There is a really good social network for older people, too,'' Professor Wesch said. ''It caters to the older generation with an automatic feed of news that relates to older generations and a number of features tailored to the way people in that generation would interact.''

''What's it called?'' I asked.

''I can't remember the name of it,'' he said.

''Exactly,'' I said. ''I'm staying where it's fun.''

But after receiving a follow-up threat from my daughter (''unfriend paige right now. im serious. i dont care if they request you. say no. i will be soo mad if you dont unfriend paige right now. actually''), I started worrying that allowing parents in would backfire on Facebook.

If the presence of people like me alienated Facebook's core younger group, would they flee? And if so, whom would I annoy?

''I can't really comment on your family dynamics,'' said Brandee Barker, a Facebook spokeswoman. ''But I can say that more than 50 percent of Facebook users are outside of college now. As our original demographic gets older, we want to be able to include their social networks.''

''Maybe I should lay off my daughter,'' I said.

''Facebook is all about being a reflection of real-world relationships,'' she said. ''The same thing you're experiencing with your daughter online is a reflection of how you're not a part of her social network in real life.''

''I thought you weren't going to comment on my family dynamics,'' I said.

To try to cheer me up, Ms. Barker said, ''I'm 36, so I'm O.K. with being friends with my mom on Facebook because I don't think she's weird anymore.''

I had only 20 years to wait.

I checked my Profile. My daughter was now my friend. Well, sort of. She had set her privacy settings to grant me only bare-bones access to her profile.

She also sent a message: ''stop worrying you'll end up writing a young adult novel in an empty apartment because even some extremely old creepsters write real novels''

''I'm glad we're friends,'' I wrote.

''oh thank god I was starting to worry,'' she wrote.

Facebook, you know too much.