1580s, "act of recollecting," from Old French reminiscence (14c.) and directly from Late Latin reminiscentia "remembrance, recollection" (a loan-translation of Greek anamnesis), from Latin reminiscentem (nominative reminiscens), present participle of reminisci "remember, recall to mind," from re- "again" (see re-) + minisci "to remember," from root of mens "mind" (from PIE root *men- (1) "to think").
The meaning "a recollection of past incidents, events, conditions, etc. within one's personal knowledge" is attested from 1811; especially, in plural, "the collected memories and experiences (of someone) in literary form." The 17c. also had reminiscency "faculty of reminiscence."