Why?

Why is it that the people who are closest to you do things that hurt you to the bone and think nothing of it???? people do things all the time and think that it affects no one but them. Why??? I hate that about people. Especially when they have been found out and act like it should not matter. People, please listen. Most things that you do in life affect everyone around you. Dont ever think that you are the only one. No matter how insignificant the situation may be. It is sometimes the small things that can make people lose faith in you. IS it worth it???