NEW YORK — At 1:30 Wednesday afternoon, it was business as usual in Brooklyn around the Barclays Center. People walked to and from their offices. People ate lunch and shopped and tried to stay out of the oppressive heat as much as possible.

We all knew that was going to change. Excitement was coming in the form of a kid from Newport, Maine.

Maine came to Brooklyn on Wednesday, in the form of 18-year old Cooper Flagg, the Newport native who is the biggest name in American sports right now. They should’ve been selling lobster rolls on Atlantic Avenue up the street from the Barclays Center, where Flagg was the indisputable toast of the NBA draft.

Shortly after 8 p.m., the Mavericks made it official when they selected Flagg with the top pick.

Carlos Concha is a huge Duke fan, so there was no question he was going to make the 2 ½-hour drive from his home in Scranton, Pennsylvania, to Brooklyn for the draft. Concha said he’s followed Flagg since his days at Montverde Academy. He was first in line waiting to get into the Barclays Center, and he held a black Flagg Duke jersey.

“You’re looking at a generational talent like Flagg, of course I was coming to this draft,” Concha said. “What he did in one season at Duke was incredible. He’s someone you can’t miss.”

Concha is 19. Like the rest of us, he marvels at what Flagg, who turned 18 in December, has accomplished basically before he could vote.

“He’s younger than me,” Concha said. “I just really can’t wait to see what he does in the NBA.”

Behind the scenes, the NBA draft is organized chaos. At it’s heart, it’s reality television. Drama for days. What player will go where? Will there be trades? What team won draft night? That drama did not extend to the top pick. Since the Dallas Mavericks won the draft lottery last month, Flagg’s destination hasn’t even been an open secret. It’s been a fait accompli.

Hours before Cooper Flagg would speak to ESPN announcers, they rehearsed how it would go, asking questions to a Flagg stand-in while crews put on the finishing touches to get everything ready. Designated Cooper spoke in clichés that those who heard the run-through hoped the real Cooper would avoid.

The athletes lucky enough to fulfill a lifelong dream would share a moment with their family before quickly ushered to the stage, where they would shake hands with NBA Commissioner Adam Silver, then talk to ESPN, then to a news conference, where they would tell the world how thrilled they are to be going to whatever city they were about to board a flight to begin a thrilling, difficult and lucrative life under the microscope. It has to be head-spinning. The biggest moment of your life, and you’re going through a car wash of obligations.

Flagg arrived at the Barclays Center just before 5 p.m. and hit the red carpet with the other players expected to be chosen near the top of the draft. First, Flagg gave high-fives to a group of kids gathered at the entrance. Then he posed for photos, grabbing the lapels of his suit and striking a pose. The red carpet is part pregame show, part fashion show, and all pomp and circumstance.

Approximately 24 hours before the start of the draft, it was business as usual in Brooklyn around the Barclays Center. People walked to and from dinner, or walked home from a day’s work. Flagg’s picture hung above the main entrance to the arena with photos of a handful of other top NBA prospects who would hear their name called Wednesday night, but the world walked by. The excitement was building, but it wasn’t there yet.

But it was coming.