the odds against chance coincidence are very great.

Dreams only form subjects of good dream-stories when the vision
coincides with and adequately represents an _unknown_ event in the
past, the present, or the future. We dream, however vividly, of the
murder of Rizzio. Nobody is surprised at that, the incident being
familiar to most people, in history and art. But, if we dreamed of
being present at an unchronicled scene in Queen Mary's life, and if,
_after_ the dream was recorded, a document proving its accuracy should
be for the first time recovered, then there is matter for a good
dream-story. {8} Again, we dream of an event not to be naturally
guessed or known by us, and our dream (which should be recorded before
tidings of the fact arrive) tallies with the news of the event when it
comes. Or, finally, we dream of an event (recording the dream), and
that event occurs in the future. In all these cases the actual
occurrence of the unknown event is the only addition to the dream's
usual power of crumpling up time and space.

As a rule such dreams are only mentioned _after_ the event, and so are
not worth noticing. Very often the dream is forgotten by the dreamer
till he hears of or sees the event. He is then either reminded of his
dream by association of ideas or _he has never dreamed at all_, and
his belief that he has dreamed is only a form of false memory, of the
common sensation of "having been here before," which he attributes to
an awakened memory of a real dream. Still more often the dream is
unconsciously cooked by the narrator into harmony with facts.

As a rule fulfilled dreams deal with the most trivial affairs, and
such as, being usual, may readily occur by chance coincidence. Indeed
it is impossible to set limits to such coincidence, for it would