The Collaborative International Dictionary of English v.0.48:

Retrospection \Re`tro*spec"tion\, n.
   The act, or the faculty, of looking back on things past.
   [1913 Webster]

WordNet (r) 3.0 (2006):

retrospection
    n 1: reference to things past; "the story begins with no
         introductory retrospections"
    2: memory for experiences that are past; "some psychologists
       tried to contrast retrospection and introspection"

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "retrospection":
   commitment to memory, exercise of memory, flashback, hindsight,
   learning by heart, looking back, memoir, memorization, memorizing,
   memory, recall, recalling, recollecting, recollection,
   reconsideration, reexperiencing, reflection, reliving, remembering,
   remembrance, reminiscence, retrospect, review, revision, revival,
   rote, rote memory, study, youth