Fandom sometimes takes a circuitous path. For example I lived in Calgary for 2 years and had an opportunity to see a Stampeders game, with Doug Flutie as the QB. I moved back home to Toronto just when Flutie was traded to the Argos. Those were great years for the Argos, winning some Grey Cups. Flutie is still loved in T.O.
Fast forward a few years and the Bills signed Flutie. I'm sure much of the reason was marketing, even though most people in the Toronto area already adopted Buffalo as their NFL team due to proximity.
Then the Bills ownership lost their minds and done Doug Flutie wrong.
Coincidentally, it was a Bills-Seahawks game in Toronto that turned me into a Seahawks fan on the spot.
So there you go.