Years go by. Hearts start to harden. Paying taxes, witnessing political turmoil, Sleater-Kinney splitting — of course your ticker’s in some kinda shape.

But around 9 p.m. on a vampire school night, here comes a feeling you thought you’d forgotten.

That was when Vampire Weekend launched into their song “Horchata,” at the not-quite-halfway point of the stellar first installment of a three-night stand at ACL Live on Tuesday. (The New York band is set to play another show Wednesday, followed by an “Austin City Limits” taping on Thursday.)

When Vampire Weekend started in 2006, a few years before “Horchata” came out, George W. Bush was president and Chamillionaire had a No. 1 hit. The band is an indie-rock institution these days, if you can believe. After multi-instrumentalist Rostam Batmanglij departed in 2016, frontman/guitarist Ezra Koenig, bassist Chris Baio and drummer Chris Tomson are joined on the Father of the Bride Tour by guitarist Brian Robert Jones, multi-instrumentalist Greta Morgan, percussionist Garrett Ray and keyboardist Will Canzoneri. Seeing these reformed preppy upstarts was destined to feel like a blast from the past.

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And Vampire Weekend’s return to Austin after more than 5 years did feel like time was bending. The band emerged to baroque strings — or, you know, some kinda old-timey strings — with the faux-pomposity that’s aged pretty well in a post-Occupy Wall Street world. Koenig’s still everyone’s wavy-haired boyfriend, saintly Tuesday night in a pale “Call Me by Your Name” get-up. Somewhere between yachtsman and meditation teacher. You won’t see many rock frontmen in Chacos. Koenig’s fingers curled on opener “White Sky,” conducting the packed house’s singalong like they were an orchestra of voices. That falsetto of his still sounds like indie-rock sonar. You remembered that no one actually knows all the words to any Vampire Weekend song, but everyone remembers to shout “Peter Gabriel!” when the time comes in “Cape Cod Kwassa Kwassa.”

But this was not a simple nostalgia trip, despite the high-octane karaoke from the crowd. As the band weaved through new songs into old ones and back again — “Bambina” into “Unbelievers” into “M79” into “Sunflower” — fans had to face the facts. Yes, Vampire Weekend might be a jam band now. It’s a meme at this point. Phish comparisons sprang out of this year’s “Father of the Bride” album.

Almost every song during the two-hour-plus set, indeed, unraveled by the end like a thrift-store sweater given a sharp tug. The guitars giggled over paisley delight “Sunflower,” and then it felt like the drugs hit when the song became a distended Laurel Canyon acid trip. You thought, “If only Joan Didion could get a load of these strobe lights.” Minutes went by — hours? — and the guitars got heavier. The drums thundered harder, and you’d spiraled into a metal interlude.

Elsewhere in the set, “Sympathy” slouched into a Tommy Bahama haze, and “2021” unspooled into piano vapor, like a pressure valve had been released. The Phish thing hasn’t felt fair to me, and it feels even more flip after seeing Vampire Weekend take their wide catalog and turn it into a cathartic live show, full of songs that felt as open-ended as anything else in this life.

In 2006, short and snappy sprints about Oxford commas and walking through the quad felt right. But now, if you grew up with Vampire Weekend, you might be thinking about the future and kids, about how you used to be happier and worry less. You once got through the day without sighing so much. You used to just plug your iPod into the aux cord in a friend’s car and not change it when “A-Punk” inevitably came on first.

No, nothing feels so short and snappy anymore, I thought as “2021” dissipated into a jazzy swish. As you go on — through the years, or at a Vampire Weekend concert — things tend to sublimate.

“Horchata,” that old fave, came up after “2021.” I realized that the line “Oh you had it, but oh no, you lost it” hit a little harder now than the funny part about wearing balaclavas.

The band probably didn’t disappoint many people looking to hear a personal anthem. You got the flight of the bumblebees of “Cousins,” the romantic glow of “Flower Moon,” even a sprawling, synthy “New Dorp, New York,” where the guitars howled like a ghost cursed to roam the earth looking for its lover. Koenig and the gang have always been concerned with time and mortality, and “Diane Young” was proof. “A-Punk,” of course, go every butt out of every seat. And Koening told the audience that he thinks it was an Austin show where someone once threw a student ID on stage, bearing the titular name of the song “Hannah Hunt.”

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If a couple of hours was too long for you to sit through an encore, tough, because Vampire Weekend had their own sense of time. Koenig asked for requests, playing “Holiday” for a fan from Mexico and “Campus” for someone in the balcony. The band used to close all their shows with “Walcott.” They don’t always do it anymore, Koenig said, but they did Tuesday.

For my money, it was “Step” earlier in the set that best tied this trip through time and space together.

“I feel it in my bones,” Koenig sang. “I feel it in my bones. … I can’t do it alone. I can’t do it alone.”

I think plenty of people packed into ACL Live, watching their playlist picks of a decade past visit the present, were thinking the same thing.

Set list:

“White Sky”

“Cape Cod Kwassa Kwassa”

“Bambina”

“Unbelievers”

“M79”

“Sunflower”

“One (Blake’s Got a New Face)”

“Sympathy”

“Rich Man”

“Step”

“2021”

“Horchata”

“New Dorp, New York” (Sbtrkt song)

“This Life”

“Harmony Hall”

“Diane Young”

“Cousins”

“A-Punk”

“Hannah Hunt”

“Vampire Blues” (Neil Young cover featuring Christone "Kingfish" Ingram)

“Flower Moon”

“Jerusalem, New York, Berlin”

Encore:

“The Kids Don’t Stand a Chance”

“How Long?”

“Holiday”

“Campus”

“Walcott”