Intimacy
Something I found in a really obscure place made me want to share:
"Strangers rarely give away anything about themselves. Lovers must trust each other with full knowledge of their true selves, and be comfortable being naked in each other's presence. Physical nakedness is relatively simple for our sexual drives carry us forward like a rising tide. But to be naked and unashamed together in spirit -- that is so much more risky, hence so much more difficult."
... and yet so very essential. When you are wearing a mask any relationship you try to maintain is based on a lie, and true intimacy is impossible.