Waiting for Godot is famously noted as being a play wherein nothing happens - twice. Vladimir and Estragon wait for someone (Godot) and it is not clear they know anything about him. They comment that the intrusion of Pozzo and Lucky helped to pass the time but that time would have passed anyway. They seem comfortable in simply passing time, and they are nonchalant about the violent way Pozzo treats Lucky. Despite the random chaos that occurs when none of the four characters can seem to stand and the pointlessness of their waiting in general, they still wait. They wait for certainty, some meaning in an evidently chaotic, meaningless world.
This is the definition of Absurdism: the incompatibility that arises when humans seek meaning in a meaningless world. Or, a slightly more optimistic interpretation of Absurdism would be the inability of humans to find meaning. This implies that there is the logical possibility that there is meaning in the universe but humans are just incapable of discovering what that meaning is.
And yet, they still wait. Despite all evidence that constructs for them a random, meaningless world, they still wait. Their failed attempt at trying to hand themselves is both comical and absurd. Absurdist philosopher Albert Camus notes that suicide, although an escape from an absurd existence, is even more absurd than staying alive and dealing with the absurd. Camus' conclusion, notably in his essay "The Myth of Sisyphus," is that the alternative to suicide is to accept the absurdity and uncertainty of life. He imagines Sisyphus acknowledging the fact that he will forever repeat pushing the rock up the hill. At least he will have the certainty in his own absurd existence.
Vladimir and Estragon are constantly faced with uncertainties. The tree changes overnight so they're not even sure they are in the same place. The last time the boy returns to tell them Godot is sick, he doesn't remember meeting them. At one point, Estragon forgets Godot's name. So, it is not just the world but the way they all think that is absurd. In the end, they actually decide to leave, but can't.
Estragon: Well, shall we go?
Vladimir: Yes, let’s go.
They do not move.
Vladimir: Well? Shall we go?
Estragon: Yes, let’s go.
They do not move.
This refusal to leave may reflect their refusal to commit suicide but it could just mean that they are bound to repeat their waiting just as Sisyphus is bound to repeat pushing the rock up the hill. Vladimir grabs the boy and tells him to make sure he doesn't forget the meeting. Facing the absurd certainty that the boy will return, having forgotten the meeting only to tell them again that Godot is not coming, Vladimir still tries to avoid the unavoidably absurd outcome.