Narcissistic abuse is about dominance and fear. When one person can make another person afraid of them in some way, it is then possible to create fear in them and control them using their emotions against them. Understanding what FEAR actually is can help us override our fear responses to some degree and help regulate them so that we become less reactive to the chain reaction fear is.
Trauma survivors are conditioned to respond to fear stimuli faster than others and that is not our fault. This is a survival response and can be helpful when we need to recall memories and reactions to fearful stimuli quickly. Trauma survivors go from 0-100 because their brains are conditioned to react quickly to painful stimuli and that is not our fault. Learning to think about our fear helps us slow down our fear reactions and thus helps us take better control over our lives.
Narcissists tend to attract people pleasers, or codependent personalities. Because codependents are eager to please, because they seek outside validation, they are easy targets for narcissistic lovers, and friends.