“Oh no, I only act narcissistic and borderline online because strangers are mean, and with my coworkers because they are abusive! Also I have a loveless marriage so that doesn't count.”
But your personalities are not what you imagine to be. Your defenses are your personalities. And your defenses will be shaped by your environment. That's why disordered parents produce disordered children, not because of genetics.
As adults, you are in charge of your personalities. That means, the people you choose to meet. The jobs you choose to leave behind. The online arguments you decide not to take part in.