This is a very sad song, but it is quite true. If you just think about it, when someone breaks up with you, you usually are a little sad and try and think why they would do that to you. You really liked them and now nothing goes right for you. So, you never think you will do that to someone else? Or maybe you already have, I don't know. But with this song it is saying that it hurts to be put down, and it is trying to say that you don't really want to do it to someone else.