"Sorry seems to be the hardest word"

Why is it so hard for as to apologize when we hurt other people , especially close ones .
It's like we take those people for granted , as if they are always there for us and they will forgive us later on . What if it leads to broken relationships and that person is gone and you can't see him /her anymore ,also what if you and the close person fought and you never came back to say you are sorry , and that person is gone forever , wouldn't you regret it, that you made something small effect you so much that you wouldn't talk to the person ,and then you'll never see that person ?.