There are Dallas Cowboys fans all over the world. This circumstance leads us to different approaches to fandom. We all share the same general fandom in that we root for the team and root against division rivals, but perhaps you also root against a team that somebody else does.
To be more specific as a hypothetical, it is possible that you live in an area that has another strong NFL presence and so that fanbase annoys you. You might live in Arizona and get sick of people talking about the Cardinals or something like that. You get the picture.