What difficulties does Meursault have in responding to the magistrate the way he is expected to? Why do the expectations annoy him?

The magistrate fails to understand when Meursault explains that he hesitated after the first shot before firing the last four. Saying he had loved Maman the same as everyone (as he truly does love everyone the same) has less of an impact than his inability to answer why he would have waited like that. The physical stimuli of the moment on the beach return to his senses, he can feel the moment, but he cannot express his motivation because there was none. He could have shot or not shot, and he shot. The crucifix being brought out represents the hinge of Camus' philosophy that there is no God. He is not a nihilist but he believes that nothing divine or absolute exists and that many people use a faith in a higher being as a crutch to avoid living and taking responsibility for this life. Life is absurd, not controlled or monitored or rewarded, and Camus thinks that to live a full life, one must face the absurdity of death leading to nothingness instead of focusing all of one's energies on an abstract and unlikely concept. Why prepare and wait when we could live?

The magistrate gets very frustrated because he does not understand this worldview. Meursault does not even feel sorry for what he did. It was an inconvenience to him to be taken from his pleasurable life and dropped into the monotonous dirty cell. The times with the magistrate come to represent the only breaks from the dark damp world of the cell and he finds pleasure in the simple cordiality of their rare interactions. Each action and encounter that Meursault delights in is indeed an understatement of the manner in which most people live their lives, overlooking these moments by searching for their meaning or accumulation. Meursault's happiness and ability to grasp it is an understatement of Camus' larger message.