In our childhood, in order to express something, we had to simply speak the words, to allow the scream, or to cry the tears. We just wanted to attract some attention and that was the end of the story.
Later on we noticed, that we also create an impression on the others, and that we can communicate through that impression we make. The expression we put on our face creates the impression which the others get from us. This way we learn to put on specific masks. We create an image of ourselves just for the others and we rely totally on what the others perform in front of us. Like this we begin to accept the mask as if it was one with the person, because we can perceive it only through the holes in our own mask. In order to see through the other, we need to let go of our own false behaviour. The moment we say the truth, nobody can lie to us any more.