Answer:
Cryptomnesia
Step-by-step explanation:
Cryptomnesia is a phenomenon in which the forgotten memory gets the return. The patient does not recognize it. The patient believes that this memory is new and it is original.
This is called a memory bias. Here the person recalls the thought, ideas, tune, and the jokes. The person is not engaging in plagiarism. But the person thinks that this is a new and original memory.
This term cryptomnesia first was used by Stainton Moses in 1974. Carls Gustav Jung also introduced this term in his work Occult phenomena.