What is the theme in Brazzaville Beach: A Novel by William Boyd?

Finding one's life purpose is the major theme. An age-old theme of a significant body of literature, Brazzaville Beach offers its own discussion of man's rather universal search for meaning and purpose in one's life. Hope seems to have moved through a number of life-altering events, each of which appear to have shown her what her purpose is not. As a young intelligent woman, trained to be a scientist and married to a mathematical researcher, she forms the rather naive notion that her purpose is defined by her plant research and support of her husband in his quest to resolve issues of mathematics.