Try to understand we classify what we don't understand.
Its only the personal connection we share with others that allows us the ability to understand the person they are as they mean to us.
If you meet someone you suspect being a narcissist, it is your own interaction with them that defines them.
So, are they actually narcissistic or are they what you define as narcissistic?
Plus, without your predisposition could they be more than what you expect?
I have met plenty of people who demonstrate narcissistic behavior that have demonstrated purely natural behavior if treated with the right frame of mind.
It takes a bit of compassion and understanding but it is possible.
All I'm trying to say is never allow the first impression to dictate how you interact with someone.
Sometimes they need just a bit more time, and...consideration.
Less often, you will realize there is no saving grace.
It comes with experience but you can tell.
There are tells to a person's affinity.
One way to understand different affinities is to understand the character types.
Since I have previously tried to explain this, I won't repeat.
Suffice it to say, anyone that understands human behavior understands this.
The most important thing to remember is people tend to follow established definitives.
Good, Neutral and Chaotic.
From Scientist and Medical Professionals, they are conclusive that someone who is a Narcissist is always going to try to manipulate you, break you down to a level just below themselves, use you, try to control you, and keep you in a mental state of believing you actually need the Narcissist.
^
For myself, that behavior is rather easy to spot. And probably has more to do with the fact that I believe effort achieves goals, not using others gets you to the finish line faster...and I tend to feel used quicker than most. I call it Discernment. It's a Gift I cherish very much!!
