In Jodi Picoult's novel "House Rules," the protagonist expresses a deep concern about cleanliness and hygiene, particularly regarding food. This is evident when they state that if someone else bites their food, they must remove the portion that has been contaminated by saliva before continuing to eat. This illustrates the character's struggle with controlling their environment and the anxiety that arises from perceived contamination.

This sentiment reflects broader themes of obsession and the impact of mental health on daily life. The character's intense reactions highlight the challenges faced by individuals with similar compulsions, showcasing the intersection of personal relationships and personal boundaries concerning physical and emotional safety.