Narcissists work well against people longing for parental care. The love/hate pattern resembles parental care and discipline. When the narcissist goes from wonderful to nasty, this can cause infantile regression in the victim. The regressed victim then embraces the seemingly caring person who had only recently been so cruel. There's no place like home.
UNDERSTANDING THE PHENOMENON OF INFANTILE REGRESSION IN RELATION TO NARCISSISTIC VICTIM SYNDROME:
[narcissisticbehavior.net]
I definitely accepted behavior that should’ve been reg flags because it was modeled by my parent.