Shakespeare has Hamlet say that the purpose of drama is and has always been "to hold the mirror up to nature." The people watching Waiting for Godot are all watching themselves. Everybody is waiting for something. Maybe they don't even know what they are waiting for, but they are expecting something to happen to them and waiting day by day for it to happen. An excellent comparison is Henry James's long story "The Beast in the Jungle." As explained in the eNotes Summary of this story:
She [May Bartram] recalls a strange confession he [John Marcher] made on that occasion—that he had always felt the deepest thing within him was a sense of being reserved for a unique fate, “something rare and strange, possibly prodigious and terrible,” that eventually would happen to him and perhaps overwhelm him.
The similarity between the themes of Waiting for Godot and "The Beast in the Jungle" is so striking that one might guess that Samuel Beckett was directly influenced by James's story. We relate to these characters because we are all waiting for something--the phone to ring, the letter to come in the mail, the girl of our dreams, Mr. Right, the job offer, retirement, the big lottery prize--whatever. John Marcher, the hero of "The Beast in the Jungle," finds out what most of us find out eventually:
The fate he had been marked for he had met with a vengeance—he had emptied the cup to the lees; he had been the man of his time, the man, to whom nothing on earth was to have happened....It was the truth, vivid and monstrous, that all the while he had waited the wait was itself his portion....He saw the Jungle of his life and saw the lurking Beast; then, while he looked, perceived it, as by a stir of the air, rise, huge and hideous, for the leap that was to settle him. His eyes darkened—it was close; and, instinctively turning, in his hallucination, to avoid it, he flung himself, face down, on the tomb.
I think that this probably one of the most important questions that come out of the drama. I think that an argument could be made that this is probably one of the most important questions that governs all existence in the world.
The metaphor of "waiting" is significant for a couple of reasons. Vladimir and Estragon are waiting, fairly convinced of the arrival of Godot. Their questions, it seems, will be answered with Godot's arrival. A certain paralysis of action seems to result from this waiting. They wait and wait, convinced and talking of what they could do, but the waiting is what chains their being to taking any substantive action. Waiting is the metaphor through which we understand the futility of the life that Vladimir and Estragon live, but it is also the metaphor through which we begin to understand our own lives. The idea of "waiting" is something that reflection shows applies to our own lives, as well. How much is it that we wait for something to provide transcendental meaning to our existence, an element in which its presence will somehow eliminate the pain, doubt, and insecurity that governs our being in the world? Vladimir and Estragon wait for Godot, but the metaphor of waiting is something that applies to us, as well, seeking to find something to direct our energies towards simply so that we can avoid having to use our energies in the first place. Just as Vladimir and Estragon suffer from a moral and function based paralysis because of their waiting, the metaphor acquires significance and meaning because we, too, find ourselves waiting for external reality to do what it is that we, ourselves, need to do, but find so difficult and painful to do.
I think that the metaphor can be expanded to what values can be taken from a play that has been called "nihilist" and without much in way of meaning. Consider Pozzo's observation regarding suffering in the world:
"he's stopped crying. [To Estragon.] You have replaced him as it were. [Lyrically.] The tears of the world are a constant quantity. For each one who begins to weep, somewhere else another stops.
Beckett hides this gem in the drama to suggest how the metaphor of waiting must be replaced with something in the name of action. "The tears of the world are a constant quality" is a reminder that our waiting enables this suffering to continue. Beckett suggests that the waiting for an external reality is what helps to contribute why there is suffering and the cries of other people in the world. The metaphor of waiting is seen in a rather intense context when seen in this light. Beckett might be suggesting that in order for human beings to minimize the cries of other people's suffering in the world, waiting must not give way to paralysis of thought and action. Individuals must be geared towards taking action and minimizing these cries that are " a constant quality" in the world. It is here where the metaphor of waiting not only has a real world quality to it, but is also one that has direct application and relevance to our own lives and how we go about living them.