I was discussing my friends Anupam and Rumu about the level of students that we teach. It is the usual diatribe about how bad they are, etc. I think it is difficult for professors to put themselves in a typical student's shoes. It is not always easy to for anyone to understand everything a professor teaches. In differential calculus, there is something called epsilon-delta definition of a limit which everyone hates. It is not all that critical and the sky doesn't fall if you skip teaching it. But most professors gamely go thru the ritual of teaching it and spoiling their hour and and their students feel they just sipped world's worst drink. My take on this, if students don't understand it, skip it. If it is really important condense it, simplify it, teach it in a way one can follow. Buddha understood this very well. He devised three different means or vehicles for imparting his teachings depending on the level of his audience. All three aim for the same Buddhahoo...