I will never understand the need that some people have to qualify the terrible things they do with the reasoning that if someone did it to them, not only is retaliation acceptable, it might actually be expected.
I think that if a person goes through life with the mentality that the things that happen to them are caused only by other people, they may need to re-evaluate. There may be a bit of truth to it, but at some point, you need to take a look at your own actions and decide if there isn’t something that you can do to change either yourself or your environment.
Change has to be internal first, for you to have an external effect.