>a book about someone sitting around and doing nothing sounds a tad boring

May I refer you to the 1859 Russian classic Oblomov -- "Oblomov is a young, generous nobleman who seems incapable of making important decisions or undertaking any significant actions. Throughout the novel he rarely leaves his room or bed. In the first 50 pages, he manages only to move from his bed to a chair."

https://en.wikipedia.org/wiki/Oblomov

Oblomov is more a treatise on 19th-century Russian nobility, but I find it interesting that lethargy and lack of direction has been democratized. :)