"Is the home you build and live in for the sake of you, the person inside, or for the sake of everyone on the outside?" Thoreau
I guess the same could be said about life in general. Do you refrain from doing something you love and that brings you joy because you're worried about what everyone else would have to say about it? Do you talk a certain way or ignore how you really feel for the sake of avoiding potential alienation from others? As a society, we have it all backwards. Why do we raise our children to judge or fear being judged simply for being themselves? Why must we seek happiness and fulfillment in the fruitless attempts of owning more, more, more? People work long hours to make money that is then spent on material objects that end up owning them. Time is taken away from family and leisure because we all have this idea that our worth is tied up into the amount of materials, when in fact, we all end up with too many useless items and not enough of the really good intangibles.

Edit: here's a bit on authenticity that I found.
"Kernis' studies show that people with a sense of authenticity are highly realistic about their performance in everything from a game of touch football to managing the family business. They're not defensive or blaming of others when they meet with less success than they wanted.

Eastern spiritual traditions have long furnished ways to glimpse the messiness of the self, and to view with detachment the vicissitudes of mind and emotion that roil human consciousness. Buddhism takes the self in all its variability as the principal subject of contemplation; the yogic tradition accords self-study great importance.

The Hindu Bhagavad Gita suggests we also have a duty to act: to realize our full potential in the world, to construct or discover a unique individuality, and thereby to live authentically. You have to "discern your own highly idiosyncratic gifts, and your own highly idiosyncratic calling," Cope elaborates. "Real fulfillment comes from authentically grappling with the possibility inside you, in a disciplined, concentrated, focused way."

That lesson isn't confined to Eastern spirituality. In The Way of Man, philosopher Martin Buber relates a Hasidic parable about one Rabbi Zusya, a self-effacing scholar who has a deathbed revelation that he shares with the friends keeping vigil at his side. "In the next life, I shall not be asked: 'Why were you not more like Moses?'" he says. "I shall be asked: 'Why were you not more like Zusya?'"