On Purim you see people as they really are which is much different than they are the rest of the time. Chazal teach us that the true self is revealed after drinking alcohol. [האדם ניכר בכוסו]. How sad that all year long people are presenting to the world a persona different from their true selves. The persona, for Swiss psychiatrist Carl Jung, is the social face the individual presents to the world—"a kind of mask, designed on the one hand to make a definite impression upon others, and on the other to conceal the true nature of the individual." So it emerges that it is not on Purim when we wear masks but all year round.
I know one person who tries to be himself all year round and there are those who look at him askance. I think that it is beautiful.
Mussar Haskel: Be your true self. There is little more likable than someone who is genuine and authentic. Nobody will be able to please everybody. So be your true self.