‘Waiting’ is doing both something and nothing simultaneously; Vladimir and Estragon recognize this which is why they are in search for something to ‘do’.
VLADIMIR: We are happy.
ESTRAGON: We are happy. (Silence.) What do we do now, now that we are happy?
VLADIMIR: Wait for Godot. (Estragon groans. Silence.) Things have changed here since yesterday.
ESTRAGON: And if he doesn't come?
VLADIMIR: (after a moment of bewilderment). We'll see when the time comes. (Pause.)...
Their words are as empty and futile as their actions. There is a silence after they say that they’re “happy” which makes it apparent that they are just forcing the emotion on to themselves. The silence allows the audience to inquire if they really are happy and if their happiness is of value. Being happy doesn’t provide a function in life; Estragon wants to ‘do’ something now that they were supposedly happy. To ‘do’ something constructive is important to pass the time; the closest they can get to a functional action is to talk to each other. Having a purpose in life is probable to come with the emotion of happiness, since Estragon and Vladimir have convinced themselves to believe they encompass a purpose in life, they require the emotion of happiness to validate it. Rather than just telling Vladimir to ‘do’ something as they were “happy”, he asks him which is a technique to create conversation. The characters have blind faith in Godot, they don’t know what would happen if he didn’t come. Vladimir is bewildered when he comes to the moment of reality of contemplating that this being true would make their wait purposeless. He doesn’t want to admit that if Godot didn’t come then their long wait would have been for