[digler999]

> if something is "required."

Allow me to play Freud here for a moment. Perhaps that question more points to anxieties about not knowing 100% of the material (which, I think we can both agree is ok. nobody retains 100%. But the student may not realize that).

So maybe they ask that question seeking approval, hoping to hear "No, thats an advanced concept for advanced students wanting to learn {special advanced concept}". Obviously thats not the case, but I could see a student asking that to soothe their worries that they understand other things, but not the difficult concept.