This book is about being different. Mersault is the stranger, because he is a stranger among the people around him.
Meursault’s strangeness seems absurd, and so does his clinging to his strangeness. However, what is the most absurd is that in a way people are all strangers to other people, and yet they are ready to judge each other for it. I think this is the true focus of The Stranger.
RECOMMENDATION: The Stranger is a book for everyone who wants to read something which makes one think about human emotions, morality, and being different.