cryptomnesia

Cryptomnesia occurs when a forgotten memory returns without it being recognized as such by the subject, who believes it is something new and original. It is a memory bias whereby a person may falsely recall generating a thought, an idea, a tune, a name, or a joke; they are not deliberately engaging in plagiarism, but are experiencing a memory as if it were a new inspiration.

Cryptomnesia was first documented in 1874. The earliest case involved medium Stainton Moses, who thought he was communicating with spirits but unknowingly repeated details he had previously read in a newspaper. The term was coined by psychiatrist Théodore Flournoy while studying medium Hélène Smith, highlighting how forgotten memories can resurface distorted by imagination. Psychologists like Carl Jung, Sigmund Freud, and Jacques Lacan further explored the concept, linking it to subconscious memory retrieval, creativity, and self-misrecognition. Jung analyzed Friedrich Nietzsche's writings, suggesting his use of previously encountered material was likely unintentional.