Read "The Art of War" If you fight, you have lost, they bested you! There is always a reason to fight, but knowing that they pulled you in means they won that battle.
I'm not smart. I just don't talk and get into arguments. I don't know much, and if i were to get into a fight i wouldn't be able to back my self up. I would just be making a fool of myself, I have experienced that feeling way too much. So i avoid ways of doing so. Making a fool of myself that is.
Other times, it still might be the right thing.