Question: when we know fighting is not good for anyone then why do that silly thing with our know ones? 

Answer: People continue to fight, knowing it is bad because people are different. They want others to see things their way, and it upsets them when thy don't. They fight to try to prove that they are right and the other person is wrong. It is silly but that is how society is.
This question from the Yahoo Q&A forum is categorized in the topic: Education & Reference