The concept that the earth is like a big stage is in itself a striking metaphor, apart from the changes that men and women go through during a specific performance. The earth is pictured as a theater stage on which various characters appear for a short while and then empties out to make way for a new production. Over the centuries there have been many productions, and there will be many more in in the future. Since these productions are only make-believe, it doesn't really matter which role a person plays. He can be a king or a jester. Everything in life is only make-believe. Shakespeare has Macbeth say:
Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more. It is a tale
Told by an idiot, full of sound and sfury,
Signifying nothing. (5.5)
And Shakespeare has King Lear tell Gloucester:
When we are born, we cry that we are come
To this great stage of fools. (4.6)
The only thing that lasts is the stage itself. A similar observation was the theme of an interesting apocalyptic novel by George R. Stewart titled Earth Abides (see link below). And this thought is contained in Ecclesiastes 1:4-5 in the Old Testament:
One generation passeth away, and another generation cometh: but the earth abideth for ever.
The sun also ariseth.
Ernest Hemingway borrowed that last line as the title for his novel The Sun Also Rises.
Shakespeare seems to be suggesting, through Jaques, that there may be many different productions on the vast stage of the earth but they are all essentially the same. These days it is a fairly common experience to be watching a romantic-comedy or a cops-and-robbers movie and realize halfway through that we have seen the same movie before, only with different actors in different costumes.