The meaning of Jaques' soliloquy from As You Like It?

In Act II, Scene 7, when Jaques says:

All the world's a stage,And all the men and women merely players,

he seems to be referring to what psychiatrist Carl Jung calls the "persona."

Through the persona a man tries to appear as this or that, or he hides behind a mask, or he may even build up a definite persona as a barricade.

This suggests that all of us are acting a part which...

In Act II, Scene 7, when Jaques says:

All the world's a stage,
And all the men and women merely players,

he seems to be referring to what psychiatrist Carl Jung calls the "persona."

Through the persona a man tries to appear as this or that, or he hides behind a mask, or he may even build up a definite persona as a barricade.

This suggests that all of us are acting a part which we want the world to accept as our real selves. That is the sense in which all the world is a stage, and all the men and women merely players.

In every walk of life each man puts on a personality and outward appearance so as to look what he wants to be thought: in fact you might say that society is entirely made up of assumed personalities.
                                     Francois Duc de La Rochefoucauld

We can see other people's personae more easily than we can see our own. We see how the doctor is playing the role of doctor and how the lawyer is playing the role of lawyer. It may have been in this sense that Holden Caulfield in The Catcher in the Rye thought of so many people as being phonies. Holden Caulfield himself was obviously trying to build up a persona. It is a hard task for people his age because they have just emerged from childhood, an age when most children, but not all of them, do not yet feel the need for developing a persona. That comes with adolescence.

Well, youth is the period of assumed personalities and disguises. It is the time of the sincerely insincere.
                                                                    V. S. Pritchett

The pessimistic German philosopher Arthur Schopenhauer also felt that most people are wearing masks.

Our civilized world, then, is only a great masquerade; here we meet knights, parsons, soldiers, doctors, barristers, priests, philosophers, and the rest.  But they are not what they represent themselves to be; they are mere masks beneath which as a rule moneymakers are hidden.  

It is interesting, and somewhat amusing, to think that we do not have to go to the theater to see people acting. In fact, the best actors might never appear on a stage or in front of a movie camera at all. If an actor in a movie is playing, let us say, a judge, he is trying to act the same way a real judge is acting the part of a judge while seated on the bench. The show that Jaques is talking about is going on everywhere and all the time. People make their entrances wearing masks, and we ourselves put on our masks before we enter a setting. The mask we put on depends on the type of setting--a classroom, a party, or whatever.