Memory
Memory is stored between the body and the spark.
A fae experiences explicit ("short-term") memory in their consciousness. This includes both semantic memory (accumulated knowledge) and episodic memory (personal experiences). When diffused together, the body and spark can exchange memories rapidly, especially while the fae is asleep.
A spark creates and retains episodic memory better than a body, but both are capable of creating and retaining semantic memory.
Implicit ("long-term") memory is mostly stored in the body rather than the spark. Practically all procedural memory (such as muscle memory) remains in the body regardless of the presence of a spark. Methods such as priming and conditioning may affect either the body or the spark, if not both.
If a body and spark are resolved, then diffused after forming memories, the resulting fae's subconscious spark processes the separate memories and forms narratives explaining those memories as though they were performed by the fae rather than two parts. These memories may also be flawed independently, adding confusion. Experiencing this is superficially comparable to remembering a dream.