The larger problem is that these subjects aren't studied for their own sake. They are obstacles on the way to a degree. If people wanted to learn, they'd clear

The larger problem is that these subjects aren't studied for their own sake. They are obstacles on the way to a degree. If people wanted to learn, they'd clearly go back after the course finished, and fill in the gaps. Much like you'd have a dentist fill in the cavities they found. You don't want a painful gap in your stats understanding, right? But that isn't done. Unfortunately, the point of stats class is to pass stats class, not learn stats. The students are only responding to incentives, and society (in general) does not care about long-term understanding. You scrape by, say you "passed" -- like being fit 30 years ago -- and that's enough for the HR screen. Nobody ever follows-up.