Someone forgot to tell the Celtics they were dead men dribbling.

That no Jayson Tatum meant no shot. To pack up, and stay home.

Thanks to Wednesday’s win in Game 5, the Celtics will march back to Madison Square Garden for a Game 6 and into what feels like a dead end at the end of a decided series.

But when has that ever stopped a team from Boston winning playoff games in New York?

Because so long as Jaylen Brown is playing his best basketball — 26 points, 12 assists and eight rebounds last night — there’s life here. A pulse.

Brown pulled off his best Tatum impression with a little extra passing pizzaz Wednesday, creating for teammates at the outset of a game most talking heads, both nationally and locally, called for him to take over. You know, like Jordan, Kobe and Tatum for most of Game 4 before his Achilles snapped. Eye of the Tiger stuff.

But Brown wisely resisted, controlling the floor early with three assists and three boards around one field goal. He turned the Knicks’ increased defensive attention against them, springing teammates open for baskets, including dimes to Derrick White and a nifty looping pass under the basket for Luke Kornet midway through the first quarter.

Let’s talk about Kornet. The White Mutombo. He was simply spectacular.

Kornet finished one rebound and three blocks shy of a triple-double. Of all his rebounds Wednesday, bouncing back from a disastrous series start was his most critical. The Celtics need center relief while Kristaps Porzingis’ mystery illness continues to sap him of all his basketball powers.

Kornet dominated the paint, finally tilting the floor back toward the Celtics when the Knicks deployed two bigs; a lineup that had been dogging Boston. Kornet blocked Karl-Anthony Towns twice in the third quarter, and Jalen Brunson whose foul baiting is now beyond shameless.

Kornet’s performance feels like the least sustainable looking ahead to Game 6, but simply finding an answer to the Porzingis problem — taking him off the floor — feels like a win. The Celtics may opt for more Payton Pritchard or Sam Hauser (welcome back, by the way) than Kornet in Game 6 and go small and stretch the floor. At least, for now, they have options.

And, most importantly, time.

Time to example how they can replicate sinking Brunson and Towns into foul trouble Friday night; foul trouble that neurtalized them both and prevented the Celtics from sliding in yet another second-half collapse.

Time to talk themselves into a comeback, even as Tatum remains laid up in the hospital.

And say what you will about the Celtics while you have time.

For most of this series, they’ve been out-toughed, out-coached, out-played. It’s all true. The Knights literally took this series from them, starting when Mikal Bridges ripped the ball out of Brown’s grasp to end Game 1 and stuffed Tatum to cap Game 2.

But as Brunson pushed, poked and prodded their defense, the Celtics punched back.

And Friday night, they’ll keep on punching.