We rarely remember things as they actually happened. Rather, as memories are encoded, they are altered in order to be made compatible with our existing knowledge; upon retrieval, memories are reconstructed rather than reproduced. Because the extent to which this reconstruction occurs can vary, some memories are very accurate while others are a mixture of fact and fantasy. Yet others - claims of highly implausible events such as alien abduction and reincarnation, for example - are completely fabricated.
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