I think that while it's good to learn about behavior patterns that narcissists exhibit that can be hurtful, it's important not to just decide a person that hurts you in some way is a narcissist. There are different challenges people can have that can result in that person self protecting with behaviors that can seem self serving and cold. Remember, we all have "some" narcissism and that means some people may have certain behaviors that might seem narcissistic but that person is not so much so that that person is "disordered" and not able to have any caring or empathy.

The most important thing to pay attention to is that if a person consistently disrespects your personal boundaries, despite your effort to express your boundaries then it's best to distance yourself from this person.