Albert Camus may have chosen his title "The Stranger" to show how the narrator feels and is made to be a stranger in the story.
It is indeed an effective story for the protagonist became and remain a stranger to all of the characters even till his death.
Explanation:
Albert Camus may have chosen "The Stranger" as his title of the book to show how his main protagonist may have become like a stranger to everyone else in the story. The protagonist Meursalt seems indifferent and even 'heartless' to all of the other characters throughout the whole story.
Meursalt was first projected as being emotionless at the funeral of his own mother. Then, he killed an Arab man while defending his friend Raymond against the latter's ex girlfriend's brother and friends. This landed him in his present situation, imprisoned and waiting to be hanged. During all of these trials, his personality and approach towards others were used as a means of judging his innocence or guilt. And considering his social life, he was found to be too inhumane towards others. His ex girlfriend accused him of being cold, stating that they went out on a movie date right after the death of his mother, and that too, watching a comedy.
The prosecutor uses the quiet nature of Meursalt as a sign of his guilt and remorse, leading to further speculation of his behavior the whole time. His inability to shed tears during his mother's funeral and the fact that he did not believe in God further 'proves' his guilt. His outburst about others having no right to judge him when they don't really know him was also taken by the court as a sign that he is indeed guilty.
The whole demeanor of the protagonist before, during and after the trial shows his reluctance to be among people, his own independence and maybe even his 'original' nature of just being a quiet man. He may seem indifferent at certain times but that doesn't mean he is a bad person. But at the end of the story, he was proven guilty and waited for his execution. He remains a stranger to everyone till his death. Thus, Albert Camus is right in titling the book as "The Stranger".
