I have come to the realisation that most students seem to keen up so much when a piece of work is going to be marked and counted towards their final grade (compared to when the work is not assessable). It draws a very close resemblance to people keening up when doing a job that they are paid to do (compared to when doing something that is not paid). So when you are young your goal is to get good grades. As you grow older and finish studying, you goal is to make good money. So marks and money are in some ways isomorphic.