All the world's a stage
All the world's a stage is the opening line of one of Shakespeare's best known and most quoted monologues. It occurs in his play As You Like It. Even people who do not know the source of the quotation may use it readily in conversation.
The passage is generally used to suggest a certainly falseness or fake quality about human behaviour. In Elizabethan times, however, it was a widely-recognised metaphor that the stages of human life are like the acts of a play.
The opening lines of the quotation are:
"All the world's a stage,
And all the men and women merely players;
They have their exits and their entrances;
And one man in his time plays many parts,
His acts being seven ages."