Well, you can’t say this terrain is unfamiliar to the Jets. Way back when, when the air was thick and warm and the days were long, back in the peak of summer, this was a team burdened by few expectations. They’d won six games the past two years. What was a reasonable goal back in August, five wins? Six?

“We know y’all don’t believe we can be good,” linebacker C.J. Mosley had said in the days leading up to the season opener against the Ravens. “We know what people are saying on the outside.”

He was right, you bet he was. This wasn’t some invented circle-the-wagons, nobody-believes-in-us fever dream. It was truth. It was reality. Few believed the Jets could be anything resembling good. The Jets were officially a show-me team: Until proven otherwise, it was going to be another slog of a season.

Then, across 12 weeks and 11 games, the Jets did everything imaginable to disprove those doubters, piling up seven wins against four losses with three different quarterbacks, an array of featured running backs, one rookie standout on either side of the ball and a defense slowly climbing toward elite chiseling a new plot for itself.

“This doesn’t surprise anyone in this room,” Quinnen Williams said after the Jets beat the Bills on Nov. 6.

That it surprised almost everyone outside the room was beside the point. The Jets really had circled the wagons. They really had ignored the prevailing belief that they were still buried in quicksand, just up to their waist this time and not their shoulders. They did that. It was real. It was legit.

It was fleeting.

And now here they are again, back in a familiar place, the rest of football ready, if not eager, to cast them out of the “in-the-hunt” graphics and out into the lonely universe of pretenders. It doesn’t take much. It doesn’t take long.

They are on a three-game losing streak and yet the first two-thirds of it, a gut-punch decision in Minneapolis and a frustrating loss at Buffalo, were treated as positive signs. The Jets could hang with the league’s best.

But Sunday’s distressing loss to Detroit reversed a lot of that momentum. They are 7-7 now. It is hard to find anyone who isn’t in the employ of the Jets who believes they can do what is an absolute requirement now: Close out the season with three wins, get to 10, and force someone else to elbow them out of the 7 seed and a likely trip to Kansas City.

That starts Thursday, against the raging-hot Jaguars, fresh off an improbable comeback against the Cowboys, a team suddenly in the hunt in the AFC South which already has wins over likely playoff participants Dallas, Baltimore, Tennessee and the Chargers. And, of course, has Trevor Lawrence at quarterback, the shiny trophy for having successfully and barely out-failed the Jets two years ago, 1-15 to 2-14.

The Jets are narrow favorites. That sound you hear is a nation of gamblers falling over themselves betting their Christmas bonuses on Jacksonville before that number changes.

“You’ve got to stay in the moment,” Jets coach Robert Saleh said this week. “You’ve got to stay process-driven. If you start thinking, ‘you’ve got to win this-one, this-one, this-one’ … you’ve got to win the moment. You’ve got to win at practice, got to win in meetings, win the next day, the next day, do the best we can in the game, and you trust the result will be what you want.”

That is exactly what Saleh has to say.

But the reality is starker than that.

The Jets could go 3-0 in practices this week, 30-0 in their meetings, but if they go 0-1 on Sunday, their season could officially die before Christmas Eve. It’s really that simple. The Jets have to win Thursday, savor that for 10 days before flying 3,000 miles to Seattle for New Year’s Day, then hope to keep the merry train chugging to Miami for a game in which they could either be battling for a plane trip to Arrowhead Stadium or looking to play spoiler. And who wants to play spoiler?

The Jets thrived best this year when there were about a hundred players, coaches and staff who believed when nobody else did. Well, that’s sure the way it feels all over again, 14 games and 15 weeks later. Maybe it’s just what they needed.