Cavorting in their newfound fountain of youth, the six struggling actors of “Friends” first splish-splashed into view on Sept. 22, 1994. They ended the show’s trademark opening segment with a group flex, not certain whether their coming-of-age comedy really would show any muscle.

All had been bruised by previous sitcom failures, and who knew whether “Friends” would be just another 90-pound weakling on a then-struggling NBC?

A decade and 235 episodes later, Courteney Cox Arquette, Matthew Perry, Jennifer Aniston, David Schwimmer, Lisa Kudrow and Matt LeBlanc are famed names with big money and a signature sitcom in the bank. The fountain also remains in play, but now it’s soaking the rich — and not so young and restless.

They’ll be there for the last time on Thursday’s one-hour end of “Friends.” Should it be called “The One Where America Gathers to Laugh, Cry and Bid Them All Goodbye?” That’s the long and short of it, but this episode is simply titled “The Last One.”

So what has “Friends” wrought besides multimillionaire stars, a hit theme song, Top 10 ratings for NBC, imitated hairstyles and major dividends for Starbucks via the show’s scene-setting Central Perk cafe?

Its lasting impact reverberates from the show’s basic premise. “Friends” began as the saga of six twentysomething New Yorkers whose family largely consisted of each other. They were single and on their own, making ends meet without incoming cash from the folks. Lone holdout Rachel Green (Aniston), still in her wedding dress, entered this self-sufficient mix after running from her impending matrimony.

In the premiere episode’s most emblematic scene, Rachel weaned herself from Daddy’s credit cards by dismembering them one by one while the gang chanted, “Cut, cut, cut!” Then Monica Geller (Cox Arquette), Rachel’s new roommate, sealed the deal by telling her, “Welcome to the real world. It sucks. You’re gonna love it!”

And so it does. And so she has.

“Cheers” and “Seinfeld,” which preceded “Friends” on NBC, began rebuilding the basic sitcom foundation. But their unattached characters were both older and appreciably more insular. Sam Malone and George Costanza don’t exactly bespeak youth culture.

NBC initially wanted to have it both ways with “Friends,” too. The network feared the show would be perceived as too generational, co-creator David Crane recalls.

“They pushed for us to have an older character,” he says. “You know, where’s Pops, who owns the coffee house? Or couldn’t there be some sort of older cop ambling in? We had to make the argument over and over again that in fact it was not a show for a generation. That in fact it was a show for everybody.”

That’s since become an argument against a show. Save for CBS, the major broadcast networks now are interested only in shows appealing primarily to advertiser-craved 18- to 49-year-olds or, better yet, ultra-advertiser-craved 18- to 34-year-olds. “Friends” instantly hit a bull’s-eye with younger viewers, spawning a cavalcade of pale imitations centered on the trials and travails of single, white Manhattanites. “The Single Guy,” “Caroline in the City,” “Conrad Bloom,” “Veronica’s Closet,” “Fired Up” — OK, we’ll stop.

Meanwhile, “Friends” has just kept going, running through a few false stop signs whenever the cast united as one to demand more money. Their salaries have grown to $1 million apiece per episode, but the series’ longevity really isn’t entirely about lucre. All involved genuinely enjoy one another’s company. Their on-screen chemistry is an extension of enduring off-screen friendships.

“Friends” will live on in DVD sets and syndicated reruns.

“Friends”‘ singular contribution is its appeal to a new generation that hadn’t been seeing much of itself in prime time. Beyond that, it simply sought to be funny, which in reality is no simple task.

“When people ask us about where we are in history, it’s kind of a daunting question for us,” Crane says. “I’d like to think that years from now, people can look at the reruns and say, ‘That is still a really funny show. And it’s also really sweet.'”