Like an apparition, an apperception unexpectedly comes into focus. It's that "a-ha" moment when a new idea integrates into one's body of knowledge.
"Apperception. This is indeed a word to conjure with—a word much used and much abused, but when rightly understood it is of great importance to teaching."
—Dean George C. Enders, "The Nazarene Teacher," Herald of Gospel Liberty, Feb. 18, 1915