When you consider that the society of the play is composed of four miserable people who have little hope for a reprieve from the misery, it becomes clear that Beckett is exploring the theme of disillusionment and its affect on the individual. We have absolutely no idea what has happened before the play opens, but quickly learn that Vladimir and Estragon live the bleakest of existences and don't even seem to have the energy to complain about it too much. They are homeless and starving, forced to sleep in ditches and steal the meager amount of bad vegetables they can carry in their pockets -- radishes and turnips that they eat raw. They get beat up by unknown others at night. They can barely remember who they are, where they are, what day it is, or any significant elements of their lives. The one positive thing they hold on to is the fact that they remember they are waiting for Godot. They hope that Godot will tell them what to do; they are waiting for direction. But even on that note, Vladimir has a more confidence than Estragon that Godot is going to actually show up. Estragon even forgets about Godot a good number of times in through the play. The two men contemplate suicide, but don't act on the idea. They seem, to me, almost beyond disillusioned. They aren't angry at their situation; they don't cry about their situation; they don't recall the 'good old days' and question what happened. Instead, they just talk to fill the time, try to fix their boots or hat, and try to remember Godot. They are completely complacent.
The only other significant characters are Pozzo and Lucky. Lucky is treated like a beast of burden with a rope around his neck while he carries all of Pozzo's belongings. Pozzo and Lucky, like Vladimir and Estragon, seem to completely accept the status of things and act as if this kind of human slave situation is normal. Pozzo too questions nothing. We know little of his background except that he has access to better food and a human slave. Beyond that, nothing. He doesn't question his situation either. He too seems beyond disillusioned. Lucky can't even speak in intelligible thoughts, so he is clearly beyond disillusionment, lost in his half-human world where he mindlessly obeys orders.
All of these characters spend their time in the play passing the time and waiting for the next thing to happen. They don't take any meaningful actions for themselves as individuals. They don't make any choices which could change their lives. Lucky and Pozzo disappear from the scene, and Vladimir and Estragon just stand around waiting for Godot.