Fighting with someone when you're not even sure what you're fighting about. As if the start of the fight was "you ate my apple and I don't even like apples!" Fighting just for the sake of fighting, with no actual point or objective.
Joe: What were you and Cindy fighting about last night?
Tom: I don't know, we were just fighting about apples.
Tom: I don't know, we were just fighting about apples.
by The Rue October 2, 2009