Why, you may ask, did the Washington pro football team act as if it had won something of massive importance Sunday, such as perhaps a spot in the Super Bowl, when it edged the lowly Detroit Lions, 19-16, with a 39-yard field goal with 16 seconds to play at FedEx Field?

Why would rookie quarterback Dwayne Haskins, after posting a bad 47.5 quarterback rating for the day, get so excited at making a couple of good plays during the final drive that for the final kneel-down play he was too distracted taking selfies with fans in the stands to be where he should have been — under center for the last snap?

Why would every part of this team act as if improving to 2-9 — when the franchise sold itself the entire offseason as a playoff contender — should be cause for joy and serial self-celebrations, individually and in groups?

Because for this team, as awful as it has been this year and as putrid as it has been at home the past 13 winless months, that’s how vital it felt — to it. As brutal as the NFL is and as many pressures as always seem to rip at this team, let it have this moment.

“It’s just so nice to get a win. The fans deserve it. The organization deserves it. You deserve it [nodding at reporters],” said perhaps overly generous kicker Dustin Hopkins, whose four field goals and extra point, along with rookie Steven Sims Jr.’s 91-yard kickoff return after a muffed catch, accounted for all his team’s points.

“It’s just good for the future. . . . It would have been so easy for us to fold,” added Hopkins, who had seen Washington go from a 13-3 first-half lead to a 16-13 fourth-quarter deficit. “It’s good that guys stuck together — even to give us a chance at the end.

“I’m just glad for us.”

Fans can be found, plenty of them perhaps, who will say, “Oh, now they win — when losing would be the smart play to get into the best position for the 2020 draft. Don’t they read the standings?”

Oh, they read them. And they hate them. Then they ignore them — as they should. On Sunday, two of the stinkiest teams in the NFL played competitive games and even held leads before coming up short; Cincinnati (0-11) and the New York Giants (2-9) got the best of both worlds — signs of improvement and a useful defeat, too. Miami (2-9) just got thumped. Washington, by winning, is now tangled up with that whole miserable bunch and is only one game ahead of Atlanta and Denver in the draft-pick race to the bottom.

Two more inspirational wins such as this in the closing five weeks, including a home game against the Giants in December, and Washington may end up with the kind of 4-12 season that, from a long-term perspective, is the biggest waste of time imaginable in the NFL. You suffer but get little for it because the gap in draft-pick value is so great between No. 1 overall and a mere fourth or fifth overall.

But you can’t fine-tune wins and losses this way — not in the NFL anyway — because the players just won’t let you. They try, and out of self-preservation in a culture full of violence, they usually try very hard because their futures and their job security are always at stake. Every coach, too. The film is your friend or enemy long after the last play.

So you see players such as Haskins going over the moon when the facts should whisper: “Modesty, big guy. You didn’t do much right — until the end. Just thank your team and your lucky stars.”

But that’s hard to do.

“It felt great just . . . playing this game with my guys and have some fun doing it,” said Haskins, who was 13 for 29 for 156 yards, one interception, one lost fumble and an overthrow of an uncovered — not just open but literally uncovered — Terry McLaurin for what should have been a 10-yard touchdown. Washington settled for a field goal.

Haskins now has a 55.9 quarterback rating — the second worst among the 35 NFL quarterbacks with more than 100 pass attempts. In a pass-friendly league in which stars have touchdown-to-interception ratios such as 24-3, 21-3, 19-2 and 17-2, Haskins is 2-6. As expected after only one year as a starter in college, he doesn’t look comfortable reading defenses, and, unexpectedly, he tends to fumble.

But he has size, toughness when clobbered, a bit of scrambling ability and arm talent, at least when he doesn’t overthrow. And he does not lack confidence, which is probably essential with this beaten-down franchise that often begs to take its lumps and gets them.

Of his missing-in-meaningless-action moment — taking the selfies, which forced respected veteran Case Keenum to do mop-up kneel-down duty, Haskins said: “I was so hype, I broke a water bottle. I look up, and we’re in victory [kneel-down formation]. I thought the game was over with already, but I’ll get it next time.”

“We were looking for him, too,” elated and forgiving interim coach Bill Callahan said. “No, I don’t laugh at it. . . . We’ll address that.”

Don’t address it too much and laugh at least a little. The old NFL quarterback fraternity is already having an “OK boomer” holiday.

What I saw was a young quarterback with almost everything imaginable still to learn about playing in the NFL but the heart and talent to shrug off a bad day and, in the final 33-yard drive, flush up the middle for a no-slide, 11-yard gain and then, on third and five from the Detroit 38, complete a 17-yard pass to McLaurin’s fingertips to set up the winning field goal.

Of his connections with McLaurin, his teammate at Ohio State, Haskins said: “We’re going to be here a while and win a lot more games like this. . . . We’re going to make big changes around here.”

If Haskins doesn’t get a lot better — a lot better — he will be a bust. But Joe Gibbs always said that toughness was the No. 1 quality in a quarterback — physically, in absorbing punishment, and mentally, in constantly bouncing back from bad plays or games. You can’t teach those qualities, and Haskins may have them, plus the size and arm.

Before this game, played in front of a paltry crowd that paid as little as $4 online for a ticket to get into the matchup of losers, I watched the burgundy-and-gold jerseys of the die-hards — the ones for whom this win was not meaningless. Decades of prominent players were represented, with more Sean Taylor and John Riggins jerseys than for all current Washington players combined. But that wasn’t hard, because I gave up after 20 minutes — after one Brad Johnson too many — before I saw the second jersey of any current Washington player.

Right now, the die-hards may be seeing the beginning of something with rookies such as Haskins, McLaurin and kick returner Sims, as well as linebackers Cole Holcomb and Montez Sweat, who both had sacks. Given this team’s past performance, I won’t be betting on it.

But for a day, in a brutal sport, victory brings a bit of dignity. Even if you act so giddy in the process that, perhaps, you give away your scary secret — you have no idea when you will be able to celebrate again.