Cornish narrowly defeated Milos Raonic, the first Canadian men's singles tennis player to achieve a top-10 world ranking, and Kaillie Humphries, who dominated the women's bobsled circuit this season, for the honour.
"I really didn't know anything was going on, I was just getting ready to go for a day of work," said Cornish, employed as a bank rep in Calgary during the off-season. "My phone is always on silent so my iPad was getting most of my notifications and it started making a lot of noise and so I was wondering but I was playing video games so I wasn't really too worried about checking my iPad.
"But then (Stampeders communications director) Jean Lefebvre called and informed me that I had been selected . . . this was a nice little addition to my day."
And in a truly CFL moment, the 29-year-old Cornish spoke to reporters during a conference call while on a break at the bank Monday.
Cornish became just the third Canadian to win the CFL's outstanding player award after rushing for a league-high 1,813 yards. That broke his own record for the most rushing yards in a season by a Canadian.
The native of New Westminster, B.C., also led the league with 2,157 yards from scrimmage and 14 TDs en route to being named the CFL's top Canadian for a second straight season.
He's the first Canadian to win the CFL's top player award since Ottawa Rough Riders tight end Tony Gabriel in 1978 and the first CFL player to claim the Lou Marsh award since legendary Ottawa quarterback Russ Jackson did so in 1969.
But moments after Lefebvre had informed Cornish, the Stampeders star received a call from his mother, who fittingly was the first person he shared the good news with.
"She didn't know I had been selected, she just called," Cornish said. "And then I told her so it was good timing on her part."
Damian Warner, figure skater Patrick Chan and Chicago Blackhawks captain Jonathan Toews were the other award finalists.
The trophy is awarded annually to Canada's top athlete as selected by representatives of Canada's leading news organizations. It's named after a former Toronto Star sports editor.
Cornish was a finalist for last year's award, won by women's soccer star Christine Sinclair.
"To have my name mentioned alongside Wayne Gretzky, Mario Lemieux, Sidney Crosby, Steve Nash, Christine Sinclair," Cornish said. "It's insane to me that I could be selected.
"I'm still sort of taken back by, I don't want to say the repercussions but the possibilities that this award sort of creates."
And for Cornish, he hopes winning the Lou Marsh award will result in future football players aspiring to be recognized among the country's best and biggest athletes.
"In terms of true Canadian superstar athletes playing football there's not many," he said. "The recognition I get, people will see, 'I can get that recognition,' and they'll try and strive to do the same things I've been trying to do.
"I love the sport of football and so knowing we can be eligible to win this award through football will probably encourage people to push themselves a little bit harder and maybe we can get more Canadian football players winning the Lou Marsh award."