The loud version of authenticity — saying the unfiltered thing, announcing what you are like — is the one that gets performed. The real article is quieter and harder to spot from outside.
It shows up as consistency across rooms: the same manner with a stranger on the phone as with people who already like you. Anyone who has watched you handle a queue, or a waiter, or a slow website knows more about this than someone who has heard you describe yourself. Pride in it is earned in exactly those unremarkable places.