SOUTH BEND, Indiana -- It's hard to believe Jafar Armstrong was once a Kansas high school receiver who was known as a "body catcher."

You know, the type that lets the ball come to him instead of reaching out to beat defenders it. You can't question a receiver much worse than that.

In South Bend on Saturday night, a wide-eyed Armstrong drank in what means to be at the top of the Notre Dame world.

"A guy in his first game ever, to score two touchdowns, there's nothing like it," said the redshirt freshman.

The statistics were minimal. Armstrong carried 15 times for 35 yards. But his two first-half touchdowns contributed mightily to a 24-17 win over Michigan.

Armstrong angered some Missouri fans in 2017 by switching his commitment from the Tigers to the Irish. But it's … Notre Dame. You don't need to walk around this tradition-rich campus very long to understand an education here is a 40-year decision, not a four-year decision.

Armstrong came to Notre Dame as a top-100 receiver, the holder of the Kansas state career receiving touchdown mark (45). Draft departures and dismissals, though, led to an early shot at tailback.

Former Heisman Trophy candidate Josh Adams left early for the draft. Deon McIntosh and C.J. Holmes were kicked off the team. The idea was for Armstrong to "cross-train" at receiver and running back.

"Coach said, 'We depend on you, you have to be a running back,'" Armstrong recalled. "They liked what they saw in the spring."

On Saturday, the Irish couldn't have won without him in the backfield.

"It's going to be awhile before he gets all the nuances," Notre Dame coach Brian Kelly said. "He's an elite football player. He's just really raw. He runs as you see, high -- but he can catch it, and he's physical. He's game. He'll go as long and has hard as he can. You love that about players that just don't get tired."

South Bend felt like a party on Saturday night. USATSI

This is what it looks like when everything is humming at Notre Dame. A win over Michigan will inject that kind of optimism. Still, few except the truest of believers can be thinking of the College Football Playoff, but with the dawn of a new season, it's OK to dream.

The Irish should be 4-0 when Stanford comes to town Sept. 29.

"That's what it felt like, it's a playoff game -- Michigan-Notre Dame," Armstrong said. "It's a slobber-knocker, man. I'll definitely take this in, a memorable night in my life."

This is also what it looks like when everything is humming: Kelly has gone from hot seat (after 2016) to maestro beginning his ninth season coming off a 10-win 2017 campaign. Only three coaches in the history of the program have stayed longer. If Kelly makes it to 2022, he'll tie Knute Rockne for longest-tenured ND coach (13 years).

"This is culturally the best program has been in my 11 years here," Irish athletic director Jack Swarbrick said. "It was such a focused business-like six week camp. Not a single issue. As an AD, that's a little unusual."

Notre Dame has transitioned that flow to the regular season. It's not only Armstrong who seems to have slid into a role. 

The defense now looks like one of the nation's best. Defensive lineman Jerry Tillery (three tackles, one sack, one hurry on Saturday) looks like a pro. Defensive end Khalid Kareem had nine tackles, two sacks, a forced fumble and a hurry.

Quarterback Brandon Wimbush completed less than half his passes last season. That's unheard of for a major-college starter. At least 100 qualifying quarterbacks tracked by the NCAA in 2017 were more accurate.

Kelly will take what he got on Saturday all season from his quarterback. Wimbush added more authority to his passing, completing 12 of 22 for 170 yards. More than that, he was a difference-making runner taking 19 carries for 59 yards.

"It just feels like you're playing football again," Wimbush said. "I had so much fun out there not worrying about anything else."

The idea is for Wimbush not to wear out as a rusher, Armstrong to keep developing, and the defense to set the tone.

Playoff team? Just don't let the dreams get too magical.

"When you feel pretty good about the physicality of your team -- the defensive line, the offensive line. Your quarterback is a spark. … That's a pretty good football team."