I like to collect quotes (of mostly irrelevant things) so here are a few, but I don't know how relevant and useful these actually are.
"Often, it’s not about becoming a new person, but becoming the person you were meant to be, and already are, but don’t know how to be." - Heath L. Buckmaster (Box of Hair: A Fairy Tale)
"Nothing of me is original. I am the combined effort of everyone I've ever known." - Chuck Palahniuk (Invisible Monsters)
"Most people are other people. Their thoughts are someone else's opinions, their lives a mimicry, their passions a quotation." - Oscar Wilde
"Time is the enemy of identity" - Michael Moorcock
"In contrast to how a child belongs in the world, adult belonging is never as natural, innocent, or playful. Adult belonging has to be chosen, received, and renewed. It is a lifetime's work." - John O'Donohue (Eternal Echoes: Celtic Reflections on Our Yearning to Belong)
"Our bodies know they belong; it is our minds that make our lives so homeless." - John O'Donohue (Eternal Echoes: Celtic Reflections on Our Yearning to Belong)
"We have to overcome the idea that everyone is the same." - Thumbsucker
"Don't act like somebody you're not. You do that long enough, you'll forget you were acting. And so will everyone else" - The Chumscrubber
And just for kicks:
"Today you are You, that is truer than true. There is no one alive who is Youer than You." - Dr. Seuss.