One Dublin school could be getting extra homework on Monday if Dublin topple Mayo in the All-Ireland Final - but it'll be the opposite case for the school of a former Dublin All-Star.
Former Mayo player James Burke teaches at Scoil Mhuire in Howth, while teacher and Dublin legend Shane Ryan was leading the chants in the school yard at St David's Boys National School in Artane.
It was blue Friday in primary schools across the capital, as thousands of kids turned up in Dublin jerseys and decorated their classrooms in preparation for tomorrow's Croker showdown.
Although Burke (29), who now plays with Ballymun Kickhams and previously lined out for Mayo, managed to sneak some green and red bunting into his classroom - much to the dismay of his Dub-mad pupils.
The sixth class teacher has had the decorations up on the ceiling since the start of the school year, though the kids have made sure to get their own back on him since.
"There have been so many pictures of my head super-imposed onto fellas in Dublin jerseys lifting the Sam, plastered to the door saying: 'I wish I was a Dub' or something like that," Burke said.
He joked that CCTV would be checked to find the culprits.
Meanwhile, if you happened to be in the Artane area on Friday morning, you might have thought another Viking invasion was taking place in Dublin.
Instead, it was a blue wave of young Dublin fans in Shane Ryan's school, demonstrating how loud they'll be tomorrow.
"The kids themselves had the idea in one of the classes to do the Iceland (Viking clap) and they got the whole school involved, it was a great bit of craic," Ryan said.
"We had all the kids out in the yard and they sang a couple of Dublin songs, then we got some of the older lads to lead a chant of Come on you Boys in Blue.
"You drag as much craic out of it as you can. There could be a long drought on the way, hopefully not, but you never know."
Ryan, who says his ticket for Sunday is safely locked away, will try to keep calm and enjoy the match, but that's easier said than done.
"I try to enjoy it, and I generally do, but for the Kerry match I found myself getting a little bit more vocal than I normally would. I'm far enough away from the scene now that I can just be a normal supporter," he said.
Depending on the result on Sunday, the kids in Artane and Howth may well be given the night off from homework, to get onto O'Connell Street and celebrate another homecoming for the Boys in Blue.
If Mayo win however, it might be a tiring day in the classroom for Burke out in Howth. He said he'll head straight to Castlebar to celebrate if Mayo are successful after school on Monday.
However, he is hoping his Ballymun teammates, Dean Rock, Philly McMahon, James McCarthy and John Small give a good account of themselves.
"Four All-Stars and a Mayo win," he said.
Either way, a classroom will be divided.