NFL is a difficult sport to understand. Back when I went to school, 4 quarters of 15 minutes equals 1 hour. Not for Americans. Often NFL games of 4 quarters of 15 minutes last close to FOUR hours.
It's perhaps that long to give people time to digest the truckload of stats that are thrown at you during the game, with no explanation. These Irish folk spent Thanksgiving trying to make sense of it all with classic Irish humour.
This video is from the great people at Facts.