Claiming your part helps you step out of tangles with others and yourself.
What's your own role?
See your part.
In situations or relationships with any kind of difficulty—tension, feeling hurt, conflicts, mismatches of wants . . . the usual crud—it's natural to focus on what others have done that's problematic.
This could be useful for a while: it can energize you, bring insight into what the real priorities are for you, and help you see more clearly what you'd like others to change.
But there is also a cost: Fixating on the harms (actual or imagined) done by others revs up your case about them (see JOT "Drop the Case") with all the stresses and other problems that brings, plus it makes it harder to see the good qualities in those you have issues with, the influence of additional factors, and your own part in the matter.
For example, let's say you work with someone who is unfairly critical of you. Sure, there are the ways this person is out of line, self-righteous, whatever. Additionally, there are the ways that this person is also doing good things, plus the ways that other factors—such as a distracted boss who hasn't stepped in or coworkers who like to gossip—are helping or hurting. And there is your own role as well: what you're doing—in thought, word, and deed—that's beneficial or harmful.