Before Lana Del Rey took the stage at Coachella last weekend, she rode through the crowd on the back of a motorcycle in a sparkly blue dress with her long blond hair flowing in the wind. It was her first performance at the event in a decade, and for some it recalled the bygone era of 2014 — perhaps a simpler time, when the festival was in what many consider its golden age.

In corners of the internet, Ms. Del Rey’s return to Coachella drew murmurs of agreement: We are so back.

Back to what, exactly? Great question. The phrase “we are back” — sometimes upgraded to the even more impassioned “we are so back” — is one half of a popular internet meme. When you’re back, things are good. You’re on top of the world. Your investments are up, your football team is winning, you outplayed an army of bots and scored tickets to see your favorite artist.

Or maybe it’s something even simpler. Two weeks of rain finally broke to reveal a gloriously sunny day. A reality show you like is starting a new season. You made it to the weekend.

The other half of the meme — it’s so over — is for when the chips are down. Your team loses. You have to tell your group chat that you did not score the concert tickets. The rain starts up again. Life, as far as this binary meme is concerned, is a constant fluctuation between being back and being over.

The internet encyclopedia Know Your Meme traces its origins to early 2021, when, perhaps not unrelated, Covid lockdowns began to ease and many people returned to once-familiar pleasures like dining at restaurants and going to parties.

For Sean Fennessey, a host of the movie-review podcast “The Big Picture,” the phrase helped capture the spirit of watching the entertainment industry recover from the pandemic. He is known to use it often on the podcast, including variations like “We are Johann Sebastian Back.”

“The first movie I went to in a movie theater during Covid was ‘A Quiet Place Part II,’ and I’m sure I uttered ‘We’re so back’ literally in the movie theater,” Mr. Fennessey, 41, said. “When ‘Oppenheimer’ comes out, we’re so back. When ‘Barbie’ comes out, we’re so back. When the new ‘Mission Impossible’ movie comes out, we’re so back.”

But, he continued, “when a beloved auteur’s big swing fails at the box office, we’re dead. It’s over.”

Like most popular memes, “we’re so back” is flexible and capacious. There is almost no scenario in which one cannot be either “over” or “back.” And part of the humor derives from just how quickly something can be over after it is back, as well as from the exaggerated feelings that may accompany each state of being. (Also, the phrase is fun to say. Seriously, try it. We are soooooo back.)

Tom Haynes, a journalist in London, often finds himself saying it while playing with his hockey team. “It’s like you’re describing every minor success, however arbitrary, as the comeback of the century,” Mr. Haynes, 28, wrote in a direct message on X.

Max Read, a writer in Brooklyn, said he thought of the meme in more economical terms. He compared the sharp and quick swings of being “back” and then “over” to the fluctuations of the stock market.

“You look at all the economic sentiment readings, and by most measurements the economy is booming, but nobody seems to think it is,” said Mr. Read, 38, who wrote about the phrase in a newsletter last summer. “I think everyone’s a little bit nervous that something’s going to turn on a dime.”

A sense of yearning for the recent past is also inherent in being “back.” When Ms. Del Rey performed at Coachella in 2014, it might not have been a moment that anyone at the time thought they’d be longing to live again. A decade later, hindsight casts this era in a tantalizing glow of pseudo-innocence.

“Nostalgia is one of the defining cultural ideas on social media,” said Jessica Maddox, an assistant professor of digital media at the University of Alabama. “Things that are rebooted, reworked or come back up again. This is a phrase that encapsulates that.”

This sense of nostalgia isn’t only limited to memories of better times, Dr. Maddox added, but also can apply to most anything a person has already experienced. “Even if it’s chaotic and bad or ridiculous,” she said, “well, at least it’s familiar.”