If you started reading this article, hoping that I am going to answer the question, you will probably be disappointed. I will speculate on some of the reasons, but I do not know, since I am not one of the people, that value conformity highly.
I used to wonder about that subject a lot, but then I sometimes caught myself, trying to fit is. Just a little. Or asked other people, and so fat the lower counted reasons are the ones, that I came across.
The fear of argument. A lot of people do not like arguments. They sometimes try to change themselves, even their opinions and behaviour, just to minimize the possibility of the argument. They made people feel like they are in chaos, and under attack. It can produce hit-or-run response and that can bring stress with it.
The wish to be loved. The people changes sometimes themselves, because they want to feel appreciated. They think, that putting up a mask is going to make other people more appreciative of them. But on the end, the people starts liking the mask and the only way to feel loved is to become a mask, losing the real self.
The wish to impress. I have to admit, I do see myself do that from time to time. Sometimes we just do not want to let somebody else down, so we act. It is harmful, if they get the feeling that we are more capable than we really are, and expect more. Or start underestimating us, not giving us the responsibility we desire.
Taking the easy way out. Sometimes pretending can make us slide out easier from some situations. It used to be a habit of mine, but I almost completely broke it already. It is easier to pretend, there was something wrong, using the situation, that we know will make them respond irrationally.
To not get hurt. It is easier to pretend something doesn't hurt, than making peace with it and moving on. Or lying about something, so people will feel less hurt. If the people do not know the real reason, it can't hurt them. And if pretending can let you forget, why feel the pain?
Out of habit. Or instinct. This one really explain a lot of pretending. People pretend, because they always did. Or maybe the nature just simply made us that way. I don't know. Maybe we all got brainwashed as babies, and that is why we do it.
There are other reasons as well. Some I simply didn't uncover yet. So help me, what do you think are the main reasons for the people to pretend?