Estragon fooling around with his boot is one of the main emphasises of absurdity in the play. Is is unclear what he is looking for in his boot and is absurd that anything will be in his boot if he puts it back on after he checked it so thoroughly.
(Estragon with a supreme effort succeeds in pulling off his boot. He peers inside it, feels about inside it, turns it upside down, shakes it, looks on the ground to see if anything has fallen out, finds nothing, feels inside it again, staring sightlessly before him.) Well?
ESTRAGON:There's nothing to show.
VLADIMIR:Try and put it on again.
ESTRAGON:(examining his foot). I'll air it for a bit.
This also shows some backward logic of Waiting for Godot. Vladamir makes a point that if Estragon puts his boot back on, there will be something inside of it despite the procautions. Valdamir and Estagon take procautions to not move in case Godot comes however it is meaningless and pointless as Godot doesn't come at the end of act 2 either. There is also a split between the intellect and the body within the work. Vladimir represents the intellect and Estragon the body, both cannot exist without the other.
ESTRAGON:(sadly). You see, you piss better when I'm not there.
VLADIMIR:I missed you . . . and at the same time I was happy. Isn't that a strange thing?