The concern about what other fans do and what makes a true fan is crazy. The important thing is buying the ticket. Next going to the game and not being a jerk. Whatever happens in between is an individual choice - gotta leave early, thanks for coming see you next week. Our rush to judgement on what makes a good fan is insane.
I moved to a new section for the 4th after running into a friend at the end of the third. Hope the super fans in my section didn't think I left...oh and if they do and judge me as a lesser fan, tough s--t.