Some people always feel like and act like a victim. That's tiresome for everyone involved. There is lots of research about this phenomenon, and typically this victim mentality comes from early life trauma--a time in one's life when they truly were a victim of circumstances. Without good therapy, that early childhood trauma can repeat again and again in one's life. How does a person break free from this experience?
Understand the situation
Clearly it is important to understand the situation. Know where it started, how it has played out, and what can be done to change it.
Focus on victimless life
Focus on the mindsets and activities that free one from this situation--what can be done?
Help others
When you notice that situation in others, help them if you can.
Victim mentality typically has real roots, but in general is not a positive way to be--there's good research and roadmaps out there to handle this situation.