I've reviewing all I learned in my masters I finished two years ago. And I can tell you this - Effectively I remembered about nothing. About 50%-60% if presented with a problem I would have recalled that I once learned something about it in my masters but I wouldn't have recalled an "affective" / applicable amount. Enough to go back and review it quick if needed in the real world but not even enough to answer good interview questions about it. About straight up 40-50% I straight up forgot and if I would have seen it again randomly then I would have remembered it. But if presented with a problem that could have used it I would not have recalled even learning it to go back and look it up. All these classes I got either A or A+ in. I was often in the top 3 scorers of the class.