It was 1998, and Manning was entering the NFL as the first overall pick. Awaiting him in America's heartland was a first-year quarterbacks coach who had a penchant for details and an imagination for the long ball. But Manning wasn't the typical rookie. He wasn't a blank canvas like many of his peers. His reputation as a studious signal-caller preceded him. He entered the league ready to learn the NFL way, ready for Arians to mold him into one of the greatest quarterbacks of this era.
"I always called Peyton 'The Piranha,'" Arians said. "I mean, you couldn't feed him enough information. The hardest guy I ever coached was Peyton because if you had a two-hour meeting, you better have two-and-a-half hours worth of stuff ready, because he was going to eat it up and spit it out.
"Andrew has that same capability. You tell him once and he's got it. It's scary. They both have unbelievable recall."
Andrew as in Luck, the Colts' second-year quarterback, who has the unenviable task of filling Manning's shoes in the Circle City.
Like Manning, Luck entered the NFL as the first overall pick. And awaiting him in Indianapolis was Arians, 14 years after he welcomed Manning to the league. It's rare for a coach to get to tutor one franchise quarterback -- as Arians is learning in Arizona -- but he's mentored two at their most impressionable times, their rookie seasons.
When Arians turns on Sunday night's Colts-Broncos game, the flashbacks will be coming fast and often, like a Manning audible, and they won't relent. It'll be a three-hour walk down two memory lanes that look an awful lot alike.
"For me, it's very gratifying because I had both at the same time, their first years," Arians said. "As a coach, you always want to say I might have had a fingerprint on this guy, and you hope that you did.
"I have a very close relationship with all my players, especially quarterbacks. Peyton and I are still close, still to this day, and Andrew, I love to death. I'm very, very proud that maybe I had an impact on them as young players."
Bill Polian's tenure as Colts president coincided with Manning's and Arians' arrival in Indy, giving Polian a front-row seat to the budding relationship between quarterback and his coach.
"He did a great job breaking Peyton into the National Football League, teaching him what to expect in terms of defenses and in terms of tendencies," Polian said of Arians. "[He taught Peyton] how to watch tape, how to begin to formulate a game plan. He taught Peyton how to have input into the game plan. Enunciate what was appropriate. Enunciate his preference.
"It was a very strong mentoring relationship."
Polian was fired after the 2011 season, Manning's last year in Colts blue, so he wasn't able to watch Arians' relationship with Luck unfold. It's safe to guess, however, that it wasn't so different from Arians-Manning.
After spending a year with Luck, Arians has the perspective to compare the two after their rookie seasons.
There was the obvious, such as Luck's athleticism. And the detailed, such as how both quarterbacks pump-fake.
"They're so different athletically but mentally they're the same guy," Arians said. "Of course [with] Andrew, Peyton's one of his idols so he has a lot of his mannerisms, having gone to the Manning Passing Academy.
"He has pump-fakes and he does things that Peyton does, but his athletic ability supersedes anyone I've ever coached, even [Pittsburgh Steelers quarterback] Ben [Roethlisberger]. I think Ben is a phenomenal athlete for his size, but Andrew doesn't get the credit for the athlete that he is."
Manning's return to Indianapolis is being billed as the celebration of a hero, a man who is widely credited in Indiana for helping football surge on the youth and high school levels, challenging basketball as the sport of choice.
Arians doesn't think the extra attention will be a distraction for Manning, even if, as Arians joked, Colts owner Jim Irsay unveils a statue of No. 18. But as proud of Manning as Arians is, he feels bad for his other pupil in blue.
"I think Andrew is the guy being put in a tough spot because it's his home team, it's his home game," Arians said. "And he's taking a back seat to somebody, and you never want to do that to your quarterback."
On Sunday, while Arians is enjoying a rare weekend off after the Cardinals played Thursday night, he'll take in a rarer event. Two former students whose careers have Arians' fingerprints and influence on them will be squaring off.
There's no question he made Manning and Luck better, but how did the two reciprocate?
"Spoiled the hell out of me," Arians said with a laugh. "It was fun. It was great."