I've read about this a lot when I studied history. Some wars go on so long that eventually you forget what you're fighting for in the first place. You just know that there's the enemy, and they must die.
Subhanallah! so true.. its a fact we do many things not knowing why we are doing.. just because we have seen every one around doing it..
'Andhi taqleed'( may be translated as 'blind following')