Life, as I know, is full of masked people who hide emotions, weakness and are dark passengers. 

I guess we are not comfortable to show our dark side to all of them.

Everybody wants to become invisible as they put their mask on and see the world in a neutral way. By putting a mask you hide your actual identity and people start guessing who you are? At the same time, you are enjoying that moment because they can't see how you are playing with your own emotions and I know that they will never ever understand. It is not bad at all, you are just protecting yourself.

You are nothing but your shadow's mask as she also doesn't want to be visible. she always stays with you, in front of you or you can say left or right side but she never stands face to face. Shadow knew it once you know that you are just a mask, you will react and she doesn't want that.
Similar you have your own mask and that mask has another. You do this frequently but once you find comfort zone you are ready and mask will come off. As you are aware that you can't hide to yourself and when you look into the mirror suddenly you will see a reflection of who you really are.

As once mask will come off everything is open there to see. Always remember put your mask on only if necessary, don't use it for only hiding because then after some limit you will not take the mask off. And in the end when your mask leaves you will break into several parts which are difficult to rejoin. 
Even if you become master in masking of your emotions your true color will always sip through. No mask can forever hide what you are. So they get the control of your emotions and be natural as GOD also wants the same.