> Would it be impolite to ask if you consider yourself one of these authentic humans?

I wouldn't consider it impolite, but would say it's an unproductive question like all such questions of "identity" that unravel in the slightest breeze.

Perhaps a useful concept is the Hegelian take on "freedom"; that in any epoch freedom is defined by the will to overcome the obstacles one faces. There is no firmer definition of it than "intent".

A better modern word might be "lifestance" [0], a word I learned from hanging around with Rationalist/Humanist thinkers.

And here's what I think is a beautiful lifestance quote;

  """ Act as though you are free, you might get lucky. You might be
      free, who knows!  Act that way it's worth trying! -- Rick
      Roderick """

[0] https://en.wikipedia.org/wiki/Life_stance