I guess there's no difference in not learning and forgetting what you learned -or if you learned it or not.
Totally OT: According to Daniel Dennett (philosopher, neuroscientist, and head of the Department of Cognitive Studies at Tufts University), while there is a difference, depending on the timescale it's not a functional, practical difference. I.e., because the net result is the same there's no useful reason to make the distinction.
Sorry, just more useless trivia from my brain attic...