CLEVELAND — Todd Bowles did one thing right Thursday night. One. When the game was over, when the Browns had turned 14-0 down into 21-17 up, cracking open Victory Fridges all over this town, when his team had been dutifully chased back to the visitors’ locker room at FirstEnergy Stadium, the head coach of the Jets finally hit a proper note.

“I’m taking the whole ballgame,” Bowles said. “The whole ballgame is on me.”

Hell, yes, it was. This whole calamity falls square on the coach’s shoulders, all of it, from the scared-of-their-own-shadow game plan to the surplus of penalties that sabotaged them up and down the entirety of the game, up to the carefree culture that pervades this team and allows two game-changing lapses in judgment and decorum. We keep hearing these will be eradicated from this franchise on Bowles’ watch.

Things will change, he keeps saying, going on four years now.

And yet: Nothing changes. Ever. The Jets were reckless and stupid and without any kind of self-discipline in Bowles’ first three years, and they remain the same lawless train wreck now. The last two years, they were bad enough to where all of that was just a byproduct of being a lousy team.

The Jets were supposed to be past this.

“This will be a good team,” Bowles said, again, and by now it is impossible to listen to it any longer because the same things continue to befuddle the Jets week after week, game after game. That’s on the coach. All of it. Every inch of it. It was only through Providence and a good-hearted owner that he wasn’t jettisoned last year. He seemed to understand how precious a gift that was. He vowed things would be different.

Things aren’t different.

And what’s worse: It is becoming impossible to believe they will ever be different under this coach, who is now 11-25 for his past 36 games, who keeps talking tough when he’s talking to reporters but clearly doesn’t present nearly the same ferocious face when he’s talking to his players. They don’t fear him. If they respect him, as they insist they do, they have a funny way of showing it.

“Inexcusable,” Bowles called it, and that was being kind.

“We lost our composure,” he said. “Things we were doing right in the first half we didn’t do in the second half.”

Actually, things had started to go sour long before the second half. The Jets were up 14-0 and they were cruising, and they’d turned this big bowl hard by Lake Erie into a morgue. But then two curious things happened. First, while scoring his second touchdown, Isaiah Crowell added an asinine gesture to his touchdown celebration, treating the ball like a roll of Charmin before heaving it into the stands.

Then, after the Jets shook that bit of imbecility off by pounding the Browns into another three-and-out, cornerback Trumaine Johnson doubled down on the idiocy, drawing his own unsportsmanlike penalty that allowed the Browns to keep the ball.

The effects of this were both subtle and blatant: The Jets ultimately forced a punt, but instead of getting the ball back with a short field, they were pinned. That was the fine part. The obvious one was when Tyrod Taylor’s head bounced on the turf on the final play of that drive, concussed.

And into the game trotted Baker Mayfield.

You may recall that it was 17 years ago — in what should have been Week 3 of the 2001 season but, due to 9/11, became Week 2 — Mo Lewis nearly decapitated Drew Bledsoe at old Foxborough Stadium, paving the way for another kid quarterback named Tom Brady to get his first crack at the NFL. The Jets survived that time.

They wouldn’t this time, and didn’t deserve to. Give Mayfield plenty of credit for that, and give the Browns a kudo or three for seizing their moment at long last. But there shouldn’t have been a moment to seize. Crunch time should have been garbage time if the Jets had only acted with a modicum of professionalism and self-restraint, if Bowles demanded such things from this band of reckless rascals.

The Jets aren’t a good enough team to cut corners and ditch details. They are children playing a man’s game, enabled by a tough-talking coach who clearly has no idea how to create the culture he craves or ensure the accountability he preaches. The clock on him was already ticking. The hourglass was already emptying. And the griddle has been ratcheted up to about 300 degrees. And rising.