Live in Chicago and work in the North Shore for the last 7 years and I still haven't met 1 diehard NW fan. However, I know all kinds of diehard Michigan, Indiana, Mich St, Iowa, Notre Dame, and Wisconsin fans. It's really weird.Lived in Chicago for 14 years, met one NW football fan who was a diehard and grad. Met ZERO Illinois fans, zero in 14 years. Met dozens and dozens of fans from about every other Big Ten team.
Chicago is the geographic hub of Big Ten, but people from Chicago generally act as if college sports don't exist. They'd rather pay $300 to watch the Bears be horrible than pay 15 bucks to watch a ranked college team. There are tons of college football fans in Chicago, none of them are from Chicago and none of them like Illinois or NW.
It would be like somebody living in Des Moines and working in Ames and not knowing 1 diehard ISU fan, but knowing a lot of Nebraska, KSU, KU, Missouri, Iowa, Minnesota fans.