As Andy Warhol notoriously remarked: “”In the future, everyone will be famous for 15 minutes.””

Of course, since this is one of the most frequently quoted remarks of all time, it ironically ensured that Warhol’s own fame would last much longer than 15 minutes.

But the statement has served well to describe our strange celebrity culture, in which ordinary, often quite mediocre people are elevated to the status of modern-day Caesars for months or even years, only to be ultimately cast into what Leon Trotsky termed “”the dustbin of history,”” never to be heard from again.

Lately, though, I’ve begun to think that the famous never leave us entirely, but simply transform themselves into other shapes. Like the hapless hero of Kafka’s “”Metamorphosis,”” they are utterly unrecognizable as what they once were.

Take Black Eyed Peas singer Fergie, whose first solo album came out two days

ago. “”London Bridge,”” her blockbuster single, is still dancing and cursing its way across the airwaves, with the special glee only known to the temporarily trendy. As far as I knew, it was the first time I’d heard her.

Imagine my shock when, as my eyes glided across this month’s cover story in Entertainment Weekly, nodding at the usual complaints about paparazzi and confessions of one-time meth addiction, I discovered that I had heard Fergie’s voice before, in the most unlikely context I could have imagined.

It seems Fergie was once Stacy Ferguson, and she got her start as a child actor appearing in commercials for the likes of McDonald’s, before landing a spot on Nickelodeon’s “”Kids Incorporated,”” which led to a gig in long-forgotten R&B band Wild Orchid, which led to Black Eyed Peas, which ultimately led to the cover of EW.

But Fergie’s big break was providing the voice of Sally, Charlie Brown’s little sister, in two “”Peanuts”” television specials: 1984’s “”It’s Flashbeagle, Charlie Brown”” and 1985’s “”Snoopy’s Getting Married, Charlie Brown.””

They seem to have vanished from the airwaves today, but when I was growing up, the “”Peanuts”” specials, based on Charles Schulz’s great comic strip, were an inescapable part of life. With their shaky real-child voices (which often stumbled over impossibly grown-up phrases like “”big Eastern syndicate””), light jazz soundtracks (which suited the shows’ general air of melancholy and regret) and reliably predictable titles (virtually every special had “”Charlie Brown”” in the name, probably because of Schulz’s dislike of the word “”Peanuts””), they were unlike any other cartoons there were.

By the mid-’80s, though, Schulz’s animation team seemed to be running low on ideas, and “”Flashbeagle”” was far and away the most bizarre “”Peanuts”” special of them all. I haven’t seen it since I was 8, but every moment is burned into my mind.

The special, which had virtually no plot, consisted of one animated music video after another, culminating in Snoopy dressing up like Olivia Newton-John and impressing the neighborhood kids with his breakdancing. I’m not making this up.

Fergie-voiced Sally then takes a half-asleep Snoopy to school for show and tell; her classmates are unimpressed, until one of them takes out a boom box.

Learning that little Sally Brown (who, I remember, seemed to practically scream all of her lines) grew up to be what EW called the “”playfully profane”” Fergie is like finding out that the latest appointee to the Supreme Court is that little kid whose hair you used to pull in kindergarten. It just doesn’t fit.

“”Snoopy’s Getting Married”” was considerably less surreal; it revolved around Snoopy falling in love with a French poodle and deciding to get married. Fergie/Sally even sings a little song at the wedding.

The main thing I remember from this special is that whenever Snoopy’s brother Spike made an appearance, a sad little “”desert”” theme was heard. I still can’t look at a desolate, cactus-strewn landscape without hearing that music.

Reading Fergie expound on her troubles in the early ’90s (“”I would cut my own bangs, and dye my own hair and dress really freaky””), I have the creepy feeling that I am reading Sally’s confessions. After all, what else would she be doing all these years later, assuming she somehow escaped “”Peanuts”” world and was able to age?

Yet, I can’t escape the feeling that EW cover or not, little Stacy Ferguson’s career has actually gone downhill since her days as Sally.

After all, once you’ve done “”Flashbeagle,”” everything else is going to seem small-time.