It’s important to remember that just because a student knew something last year does not mean he will know the material this year. Retention is a key aspect of education that no one likes to address.
This is also true for adults. For example, if an adult obtains a masters degree, will the information be retained if not used and reviewed?
Universities don’t seem to address this issue, since selling more education and filling the seats is a key objective. American’s need to consider the reality of use it or loose it!