Being fake is never the right thing to do, but many people use this as a defense mechanism or in order to impress others. When you are being fake you can not keep up the charade forever, and eventually your true nature will come through in front of others. True friends are not impressed by what you own or what you do but by who you are and what your character is. When you are being fake you deprive others of finding out who the real you is and liking you for yourself.
Be yourself people don't have to like you and you don't have to care.