In my opinion, people do not need pretend anyone in their life. And there are some girl change their characters when they fall in love with someone. But maybe they forget why the guys love you, because your face, personality, or your natural. Whatever which parts he loves you, you must understand that if someone want you change for them, then you think they really love you. And all of people want to be respected, and they want the others to do something as the way they like. So why people so care about the face when they do something, i think it is depends on different situation, and also decided by where the people grow up, and what kind of education they accept. The environment is the important issue in our life.
And do not put the face to the important position, this is too harm to everyone who around you. At the daily life, you do not need think more about what you should do, just do what you want. We live in this world for ourselves, no one have power to judge you. If you do not respect yourself, then no one will treat you as you think.
Last but not lease, the face not important as we think, the reason why people so care about it, it is because they do have confidence to support themselves. So you want to be someone like this? No one will anwser yes.