I most of the things discussed here also apply in my case. It is actually Purna Bdr Sir who made me perfect in Math. Of course one has to write Theorm 20/30 times. Before that it was Pradeep Bhattarai who taught us Math. He is one of the worse teachers in my life and most of us were very weak in Math in his time. Imagine, we proved theorm writing "Why " in the column where we supposed to give reason for the prove. I met this guy later in TC as Physics teacher. Other were Naresh Sir who used enter class with long stick (not for beating but just to point out his figure that he writes in board), spend much time in talking and writing very neat and clean figure and teach just few minutes at the end of period. Anyway days in VN were memmorable.