lost numb sad

well it's not that i wanna complain :(
but... but....
i DON'T UNDERSTAND A SINGLE WORD HE UTTERED!
Gosh! what in the world is he lecturing about!?
adding to the point that some students actually corrected him in the midst of his lecture?
i mean, Come'on! where did they get their brain from?
...........
so how?