The illness of the wealthy
The main theme of the novel is the indolence that comes with not having to work for anything, having everything served on a silver platter, or, in other words, the illness of the wealthy. This illness is called ennui and our main protagonist is suffering from it. He doesn't see any meaning in life, and any task is boring and meaningless, which leaves him depressed. Despite the illness being described with humor and with of our main character, it is a serious issue, it takes on a grave tone when our protagonist begins to think of taking his life. The main message that the novel portrays is the message of finding ones own purpose and the satisfaction that comes from harvesting the results of ones own hard work. Once this stage in life is achieved, there is no fear of ennui.
One door closes for another one to open
Our main protagonist, despite his cynical and witty commentary, is generally kindhearted and tries to live his life righteously. His consciousness doesn't let him live life in a place that doesn't belong to him. After leaving the wealth behind, he finds himself having difficulties adjusting to a new mode of life. Nevertheless, he is glad that he followed his heart in making the crucial decision. And this decision ends up being the best one he could make for himself. It allowed him to build his life with his own work and find meaning and beauty in it. The second most important message that the author wanted to portray in this novel is the message of never giving up hope, even in the face of difficulty, because one door closes for another one to open.
