the hotel waiter, "The ability to keep
in mind half-a-dozen orders at a time"; the manager of a corporation,
"The ability to recall all the necessary details connected with the
running of the concern." While these answers are very divergent, yet
they may all be true for the particular person testifying; for out of
them all there emerges this common truth, that _the best memory is the
one which best serves its possessor_. That is, one's memory not only
must be ready and exact, but must produce the right kind of material; it
must bring to us what we need in our thinking. A very easy corollary at
once grows out of this fact; namely, that in order to have the memory
return to us the right kind of matter, we must store it with the right
kind of images and ideas, for the memory cannot give back to us anything
which we have not first given into its keeping.

A GOOD MEMORY SELECTS ITS MATERIAL.--The best memory is not necessarily
the one which impartially repeats the largest number of facts of past
experience. Everyone has many experiences which he never needs to have
reproduced in memory; useful enough they may have been at the time, but
wholly useless and irrelevant later. They have served their purpose, and
should henceforth slumber in oblivion. They would be but so much rubbish
and lumber if they could be recalled. Everyone has surely met that
particular type of bore whose memory is so faithful to details that no
incident in the story he tells, no matter however trivial, is ever
omitted in the recounting. His associations work in such a tireless
round of minute succession, without ever being able to take a jump or a
short cut, that he is powerless to separate the wheat from the chaff; so
he dumps the whole indiscriminate mass into our long-suffering ears.

Dr. Carpenter tells of a member of Parliament who could repeat long
legal documents and acts of Parliament after one reading. When he was
congratulated on his remarkable gift, he replied that, instead of being
an advantage to him, it was often a source of great inconvenience,
because when he wished to recollect anything in a document he had read,
he could do it only by repeating the whole from the beginning up to the
point which he wished to recall. Maudsley says that the kind of memory
which enables a person "to read a photographic copy of former
impressions with his mind's eye is not, indeed, commonly associated with
high intellectual power," and gives as a reason that