... teacher was punishing her for failing to pretend not to know things, so it was a bit of an extreme case.
Ditto. Teachers may routinely require students to list new vocabulary words acquired from reading an assigned text. Students familiar with all of the words may be punished for truthfully revealing this; Students are rewarded for lying and pretending to find the required number of "new words" (thereby falsifying school records that the assigned reading material was at the appropriate level for them).