How to Deal With Vindictiveness

Vindictiveness does seem to enter in there's one person doing one thing the other one said okay then I'm going to do this to you and then after being hurt it comes back. The whole thing about vindictiveness is just to understand that that person really is not worthy of your attention so I do this other thing where I have a wall in my head and every time the person does something put a brick in the wall  and over time that wall is way over my head and I'm protected from that person.