There are a lot of freeze-frames in T2 Trainspotting. In dialogue scenes, in fight sequences, in introspective moments, the film will suddenly stop and then resume a moment later. To an inattentive viewer, this might look like empty style for style’s sake, or a nod back to the flashy visuals and hyperkinetic editing of the original Trainspotting from 20 years ago. But the freeze-frames also turn the film’s subtext into text. T2 is about a group of immature men coming to grips with the fact that they are getting older. The freeze-frames — along with a steady stream of flashbacks — enable the film to do the very thing the characters want to do, but can’t: Stop the inexorable march of time, and even, for brief moments, turn back the clock to their youths.

T2 Trainspotting is about that tension, both in the lives of these men and in the wider movie industry, which is increasingly consumed with rehashing its glory days over and over. While a cynic might argue that this sequel had no reason to exist, only a sequel like T2, made many years after its inspiration to allow its actors to age in the least graceful way possible, could tell the story that this one does, or examine its ideas about mortality so effectively. The first Trainspotting was about heroin. The second is about another dangerously addictive drug: Nostalgia.

Almost all of the surviving characters from the original film (based on a novel by Irvine Welsh) appear in this one; almost all of them openly yearn for something or someone from their past. That includes Mark Renton (Ewan McGregor), who returns to Edinburgh for the first time since the events of Trainspotting, when he stole £16,000 from his best friends and fled to Amsterdam. Stepping out of the airport in Edinburgh, he’s greeted by beautiful young women in plaid skirts handing out flyers to tourists — and speaking in Eastern European accents. Mark then pays a visit to his father and learns about his mother’s passing. In an astonishing shot, the shadow of Mark’s mom seems to sit in her empty chair at the family’s dinner table. In this world, you can go home again, but that doesn’t mean the people there will welcome you back.

Mark gets an even chillier reception from Simon (Johnny Lee Miller), his former best friend, who now owns a dilapidated pub and funds his cocaine habit by blackmailing married men. Still, Simon’s doing great compared to Spud (Ewen Bremner), whose life with his wife and son recently collapsed as he fell into a full-fledged heroin relapse. And Mark’s return to Scotland also coincides, a little conveniently, with the old crew’s most violent member, Begbie (Robert Carlyle), breaking out of prison after getting denied for parole. On the run (with seemingly no interest or interference from the police) Begbie sets out to get revenge on Mark for stealing his cash all those years ago.

From T2’s very first scene, the original Trainspotting’s most memorable images are front and center. The first film opened with a blast of pure punk excitement, with Mark and Spud running from the cops while Iggy Pop’s “Lust for Life” blasted on the soundtrack. The sequel opens with more running — on a gym treadmill, which Mark promptly falls off of before collapsing in a heap. With that, the tone is set: Recreating iconic moments from Trainspotting’s past, and then deflating them. Some critics argued T2 trotted out these old scenes for lack of anything interesting to do with these characters — but in almost every case, director Danny Boyle pointedly uses Mark and his mates’ memories against them.

For example, Mark repeats and revises his famous “Choose life” monologue, but by the end of its recitation in T2, he sounds like more like an angry old man raving about conspiracy theories on a YouTube video comment section than a visionary prophet. Later, Mark finds a disgusting public toilet like the one he once dove into to recover a lost suppository. The 2017 model yields no such treasures or flights of fantasy; it’s just a crap-covered commode. (Later, a character will be felled in a fight by a toilet to the face, which in the universe of Trainspotting, is like getting your ass kicked by pure weaponized nostalgia.) And every time Boyle cuts back and forth from flashbacks of the young trainspotters to their contemporary versions, he underscores just how far they’ve fallen — literally, in the case of Mark’s first scene.

In that opening in the gym, Mark pointedly crashes into a mirrored column — the first example of many mirrors littering the film’s grubby sets. Although Begbie represents a threat to Mark, he’s not really Trainspotting 2’s villain. In fact, when Begbie finally shows up to kill Mark, prompting a chase through the streets of Edinburgh — another direct echo of the first film — Mark laughs and smiles, seemingly delighted by the opportunity to relive his youth and ignore his more existential problems for a few minutes. The guy Mark’s really afraid of is the person he sees in those mirrors, the inescapable reminder of who he’s become: A lonely loser with no family, no prospects, and no friends. (That reminder becomes even more inescapable in the climax, when Mark’s trapped inside a tiny room covered with mirrored tiles.)

When T2 Trainspotting opened in U.S. theaters back in March, its competition included a new version of Beauty and the Beast based on the 1991 Disney animated movie, and the latest reboot of King Kong. They all arrived on the back of a wave of movies and television shows either inspired by or directly continued from the popular culture of the 1970s, ’80s, and ’90s — including TV revivals of Full House, Gilmore Girls, and The X-Files and sequels to Star Wars, Jurassic Park, and Independence Day. T2 firmly belongs to that larger trend of legacyquels and long-delayed reboots, but if Boyle, McGregor, and company cashed in on this craze, they did so by critiquing the same financial impulse they exploited, in a story that constantly subverts and undercuts its predecessor’s most beloved iconography.

These meta elements also dovetail with T2’s economic subtext, and its depiction of a Brexit-era Edinburgh that has broadened its horizons through globalization while closing off economic opportunities to some of its less-educated citizens. As Mark and Simon become reacquainted, they stumble on a scam to bilk European Union out of small business grant money; their plan could essentially be summarized as “Make Edinburgh Great Again.” T2 Trainspotting is a warning about the hazards of excessive sentimentality, in art as well as life, and in addition to being funny and melancholic, it might be the best summation of life in 2017 that film has produced to date. Someone should stick it in a time capsule so future generations can try to understand why our society devoured itself while producing five movies based on a bunch of toys that transformed from cars to robots.

During T2’s climax, Mark shares a vivid memory of meeting Begbie on his first day of primary school. I don’t remember my first day of primary school, but I do remember the first time I saw Trainspotting, at the Avon Cinema in Providence, Rhode Island. I was 15 years old. (My eternal gratitude goes out to the usher who performed their job poorly enough to permit an obviously underage kid into this graphic, violent, profane R-rated movie.) I didn’t know anything about film history and I knew even less about heroin, but Trainspotting’s inventive imagery and youthful energy blew my mind. Trainspotting was one of a handful of key films I saw that summer that opened my eyes to the power of movies made outside the Hollywood system. Watching Ewan McGregor choose heroin and sink into his floorboards made me believe anything was possible.

Now, somehow, it’s 20 years later. Like the film’s characters, I’ve got a daughter, a kid, and adult responsibilities. The decades have vanished out from under us. It’s a really good life, but it’s going by so fast. Somedays, I find myself wishing I could stop time. Unfortunately, that only happens in the movies.