What is the author's style in A Man Without a Country by Kurt Vonnegut?

This novel is written from a first person point of view, that of Kurt Vonnegut, and is autobiographical narrator. Since this novel is concentrated on ideas and not on a chronological series of events, the author is a fairly reliable narrator. However, it is sometimes hard to tell, because he will intentionally make statements that are open to interpretation, and thus can be either a joke or a serious statement, or even both. Since this book is composed of philosophical ideas, based on the experiences from his life, this is the only point of view that could have worked for the novel.