The remembered fact, as a single short statement.
The absolute date (YYYY-MM-DD) this entry is tied to, or null when it
is not tied to a date. Relative wording ("next Friday") is resolved to an
absolute date when the entry is written.
ISO timestamp of when the entry was added.
One entry of a focus's agent memory: something the user told Plot about what they are trying to achieve in that focus, or standing context worth remembering.