Why does Clark, Esther's son, continually search for fulfillment and purpose in the novel, In the Beauty of the Lilies?

Clark is largely ignored by his mother, who is too busy with her career and personal happiness to give him the attention he craves. As a result, he drifts away from Hollywood, looking for work and fulfillment in various places across the country. He ends up employed briefly by his uncle, takes up with a religious cult whose leader runs a compound where drugs, and takes part in a bloody standoff causes Clark to think critically about his life and its missed opportunities.