How does Adams attempt to explain the mysterious appearances of the hitchhiker?

Adams suggests that the mysterious appearances of the hitchhiker are a manifestation of the protagonist's subconscious or a psychological projection. The hitchhiker serves as a symbol of unresolved issues or fears, surfacing at pivotal moments to challenge the protagonist's perceptions. This ambiguity adds to the overall eerie atmosphere, leaving the true nature of the hitchhiker open to interpretation. Ultimately, it emphasizes themes of introspection and the complexities of the mind.