Thread:HMcCoy/@comment-25143095-20140813045845/@comment-24808864-20140814170822

I have heard similar things, I have a class where students are being graded on how many topics they complete to mastered level, and after mastery they think that they shouldn't be tested on it again. (mostly because there is a "chance" they could lost mastery that they have already earned.

IMHO, I am pretty strongly in the other camp here. Regardless of time away, to show mastery you should be able to answer the question from the past whenever it appears again. Otherwise you do not have true mastery.