Early in my career I saw a specific lead developer being a jerk. I saw it as confidence then. Looking back I realize they were scared and were trying to cover up the fact that they didn’t know what they were doing. Time really does give clarity sometimes.

Also had seen same kind of devs. But last one caused good company to failure and so close to stop to exist.
Because my gut feeling, that he is evil narcissist, was right. Sometimes jerks are just jerks, ignorant ambitious envying fools, and only good to avoid them.