One of John Steinbeck's characters from Of Mice and Men, who is forced into a solitary life, bemoans the uncertainty of aloneness as he observes that one cannot be certain that anything is real if he leads a solitary life because he
...got nothing to tell him what's so an' what ain't so. Maybe if he sees somethin', he don't know whether it's right or not. He can't turn to some other guy and ast him if he sees it too...He can't tell. He got nothing to measure by.
This uncertainty of the condition of isolation is much the same as that expressed in Samuel Beckett's Waiting for Godot. In Act I Vladimir and Estragon have been isolated for so long in their failures and age that they both now have become unsure of their states of existence. However, they cannot even "measure" things by each other as evidenced in the reciprocity of their doubts. For example, Vladimir asks Estragon if his foot hurts and then Estragon and he reverse roles, saying the same things again:
V: It hurts?
E: Hurts! He wants to know if it hurts.
V: No one ever suffers but you. I don't count...
E: It hurts?
V: Hurts! He want to know if it hurts.
And, so they are waiting for Godot in the hope that he will provide some certainly for them; that is, they are looking for external reality in the form of another man to provide answers. Thus, waiting becomes the metaphor for attaining some meaning in life.
Nonetheless, even in their waiting for Godot, Estragon and Vladimir are unsure of the place where they are to wait:
V: He said by the tree...Do you see others?
E: What is it?
V: I don't know...A willow
E: Where are the leaves?....It must be dead.
V: Perhaps it's not the season.
E: Looks more to me like a bush.
In this doubt and uncertainty, there is no authenticity to the existence of Vladimir and Estragon. Therefore, when "nothing is certain" life is meaningless, as exemplified by the questioning of the gospels of the New Testament, what day it is, etc. Even when Estragon suggests in desperation that they hang themselves, Vladimir ignores the significance of this act, concerning himself instead with whether the tree bough they consider using would hold them. Then, he suggests again that they wait for Godot as he is curious about what ideas Godot will offer although he cannot remember exactly what he has asked him.
E: And what did he reply?
V: That he'd see.
E: That he couldn't promise anything.
V: That he'd have to think it over.
E: In the quiet of his home.
V: Consult his family.
E: His friends.
At the end of Beckett's play, the uncertainly yet remains as Estragon suggests that Vladimir's so-called knowledge may be just as unreliable as his dreams. In reaction, Vladimir asks,
V: Was I sleeping, while the others suffered? Am I sleeping now?....What have I said?
Again, even their words fail to reassure the two vagabonds. Thus, the human condition is intrinsically insecure. Perhaps, then, it is only the struggle to find some meaning itself that offers the only significance left for man.