The Mystery of the Mask

Introduction:
Before I begin, I'd like to present the disclaimer that this is more of a progression of slightly-related concepts than an official study. If you ever wondered, this is most similar to my actual brain activity. Enjoy.
Background:
Growing up, I read a lot of stories about mysterious people: spies, wizards, aliens, people in masks, hermits, the hooded man in the corner of the inn telling an unusually small person to be careful. *cough* Rangers and hobbits *cough*
Cool Stuff:
Two common themes among these suspicious characters were the obtaining of 1) a second name and 2) a disguise. An alias and a costume. For what purpose? To hide in plain sight.
You see, I grew up learning about people who had a reason to hide. People who didn't want to be recognized. I thought that was the coolest thing ever. Being yourself, but not. Disguised as someone else. Basically, being two people at one time. Inspired, I made an alias for myself, designed costumes (always involving a cape), and cut masks out of shiny black cloth.
Eventually I put away the cape (though it's still hanging up in my closet), and turned my alias into a character for a book I'm writing and will probably never finish.
Study:
It took me a long time to realize why the culture has so many stories of people who want to hide. I started putting the pieces together when I met certain people. People who didn't have my easy life. No, these folks have history. They have lived through things I cannot imagine and it surrounds them like a cloud.
I believe this is where we get the concept of "aura" or "essence." Something that is the person, but extends outside their body. I believe our experiences surround us, making it harder for people to see who we truly are, and yet easier in some ways. It's hard to see through to people who have their lives and histories floating around them, and yet, the more essence a person has, the more you can see who they truly are by all they've gone through.
[Side Note: If you're not hiding anything, but hiding behind it all, you're creating a paradox of being seen and unseen at the same time. I get the impression that people love paradoxes.]
They say a disguise always reflects the person it covers. Your personality seeps into everything you do and manifests itself in various ways. Some of those ways are your manner of speech, the way you carry yourself in public and in private, your clothing, and, most importantly, what you speak up/fight for. In actuality, it's impossible to hide yourself completely.
Most people manage for a long time to hide certain things: their darkest moments, the things that haunt them, etc. Even these should be shared at some point. This is where trust comes in. In my own experience, sharing my deepest secrets with people whom I trust allows me to begin letting go of my fear and insecurity. There is a peace that comes with knowing that someone who loves you knows what you struggle with and can help you recover.
Denouement:
I say all this, but I still don't have the answer for why people hide. I've tried to hide sometimes. I can fool people who don't know me at all, but I can rarely ever fool the people who know and love me.
I've hidden because I was hurting, ashamed, embarrassed, trying to keep a secret, planning a surprise, lots of reasons. Most often, though, I hid because of my pride. Somehow, real honesty in various situations would injure my pride. In consequence, while I protected my pride, I isolated myself from people I love and broke trusts. Hiding has rarely ever resulted in nice things. So why do I still struggle with it? It really doesn't make sense, but I want to try to be as genuine as possible.
Application:
I would urge you to identify your essence, so to speak, and figure out what you're hiding, and what you're hiding behind. What do you allow people to see about yourself and your history? What are you keeping from people who love you and want to help you? Most of all: What are you hiding from God? The Bible says in Hebrews 4:13, "Nothing in all creation is hidden from God's sight. Everything is uncovered and laid bare before the eyes of Him to whom we must give account." He can see you clearly while you pretend that He can't. If you're hiding from God, you're estranging yourself from Him, disconnecting yourself from the One who has promised to forgive your sins and make you more like Himself. It's the most beautiful promise ever and we'll just make ourselves miserable by choosing to ignore it.