There are some who wear a mask... Or many different masks. And then there are some who put up a wall.
If the different 'facades' we show to different people (or in different situations) are masks, then we are left with only different kinds of masks. There is no real face.
I prefer the wall. It signifies that people do get a glimpse of the real you but in measured bits. When discussing this with a friend, he came up with the concept of walls with holes. That is what it is. We choose different sizes and patterns for the holes depending on the people we are with or the situation we are in.
Masks hide. Walls (with holes) reveal. Whether we want to hide or reveal determines whether we wear a mask or put up a wall.
p.s. - It is interesting that one of the above mentioned people had written about this almost two years ago and i had posted a long comment in response...