for the codependent, they've been taught that their responsibility is to take responsibility for other people so they don't even know how to take responsibility for themselves and that it's even okay to take responsibility for themselves. When a codependent takes responsibility for themselves, they think that they're being "selfish" and mean. The codependent doesn't know that taking responsibility for themselves is the right thing to do and that the abusers/narcissists around them is never going to return their kindness.