understand people

Do I need to understand all the people I met? I do not think so… those people with good behavior and sincere to be my friend, I will definitely be kind and friendly to them… on the other hand, if people do not treat me as their friend and keep on threatening or bullying me, I will definitely not treat them good and I will even not talk to them a single word… sometimes, people will not willing to tell you some of the things although I keep on asking… after that, I will give up on asking and switched to other conversation… it has no point for me keep on asking… those people who threaten or bully me, I will not regard them as friend and wont even talk to them… there is also no point for me to waste time talking with them… sometimes, I do not require to understand each and every person who I had met…