Kevin Smith knows when he’s been outclassed. Or out-déclassé-d.

“When I first started out, I could impress you with bad language,” the 52-year-old director told The Post. “I can’t do that s–t anymore. Like, you turn on ‘Ted Lasso,’ they curse better than me. The older you get, though, you get other weapons, other tools.”

In 1994, Smith made a movie about his life working at a Leonardo, New Jersey, convenience store. The result, “Clerks,” was a runaway hit, a quippy (and, yes, curse-filled) seminal indie that launched Smith’s career as a prolific director, screenwriter, producer and podcaster.

He moved the “Clerks” action to a fast food joint in a 2006 sequel, but with “Clerks 3,” in theaters Sept. 13, Smith is returning to the Quick Stop where it all started. Leading men Dante (Brian O’Halloran) and Randal (Jeff Anderson) are now middle-aged and have a new focus: mortality.

As with the first one, this film is “definitely based on my life,” Smith told The Post. “I gave the characters big parts of me that make it more authentic.”

In 2018, Smith had a massive heart attack and tweeted about it from his hospital bed. Randal has a big heart attack in the film and decides to make a movie. It’s not quite the stoner hilarity of Smith’s early days.

“As much as I used to go for the laughs, later in life I’m all about the feels,” he said. “If you can send people home with a new attitude, with a new thought — ‘no day is promised; all the s–t that I’ve been putting off, I’m gonna start right now’ — then I’ve done my job.”

In his youth, he was out to impress audiences. Now, he’s hoping to connect with them on a deeper level. “Three decades into a career, if you’re not doing it just to make people f–kin’ feel, just to, like, rip open their hearts and bring them to life, then you’re just doing it for the money at that point.” And, he added with a laugh, “Lord knows, if you were going to do anything for money, you would not make a ‘Clerks 3.'”

Smith is quick to acknowledge that he’s miles from the scrappy upstart with a camera that he was in the mid-’90s.

“The first ‘Clerks’ is dripping with authenticity,” he said. “It was made by a kid who literally worked in that store, and when he turned the camera off he was ringing people up. It was boots on the ground retail experience. I can’t give you that anymore. Now I own the businesses — I’ve owned a comic book store in Red Bank for 25 years, and I just bought a movie theater in Atlantic Highlands, the one I grew up going to.”

In his first film, one of the clerks uttered the classic line, “This job would be great if it wasn’t for the f–king customers.” If he heard one of his own employees utter such a thing, Smith wouldn’t be very sympathetic.

“I’d be like, ‘You’re fired!'” he said.

Still, the new movie’s vibe is markedly softer and kinder than the original, though not without the pop culture-tinged barbs its leads lob at each other and customers. The cast includes, as always, 420-friendly duo Jay and Silent Bob, played, respectively, by Jason Mewes and Smith himself. They now run a dispensary but still like to do business stealthily on the sidewalk, like, as Jay says, “how we did in it the ’90s, son!”

Smith also brings in an array of guest cameos for Randal’s auditions for the movie-within-a-movie. Sarah Michelle Gellar, Freddie Prinze Jr., Fred Armisen, Danny Trejo and Ben Affleck all show up as locals trying to snag a part.

Rosario Dawson also returns as Dante’s “Clerks 2” love interest, Becky.

“Rosario looks like she did in 2006,” Smith said. “So when she came to set, all of us who are showing our f–king 50 years are like, ‘Hey, Ro-dawg. F–k, you’re making us all look bad. Couldn’t take the glam down a little bit, Ahsoka?'” he said, referencing Dawson’s “Mandalorian” character.

Smith has always been a director who inspires loyalty in his casts, with the same circle of people appearing in film after film. He finds it funny when the media doesn’t get that.

“We went to [Ben] Affleck’s wedding a couple weeks ago, and in People magazine there’s a picture of me and Jay in our outfits. The magazine was like, ‘Jay and Silent Bob reunite to go to Ben Affleck’s wedding!’ I was like, ‘Yeah, we reunited – for the first time since f–kin’ Thursday.'”