We mustn't model the digital library on the day-to-day operation of a
single human brain, which quite properly uses-or-loses, keeps
uppermost in mind what it needs most often, and does not refresh, and
eventually forgets, what it very infrequently considers -- after all,
the principal reason groups of rememberers invented writing and printing
was to record accurately what they sensed was otherwise likely to be
forgotten.
-- Nicholson Baker Double Fold. NY: Random House,
2001. p245.