[gdfasfklshg4]

I am coming from this from the angle of having done University level teaching. As an undergrad it seems like there is so much time and so much depth of material. When you are teaching a course you realise that there is actually very limited time and so much to cover. If you choose to dwell a long time on one topic you might well find you don't have time to expose your students to the full range of concepts that they need to be exposed to. In the UK for example you have 3-4 years to take students from finishing school to being ready to do research!