well, that didn't go well.

there is a difference between:

• being awake enough to write a lecture,
• & being awake enough to give a lecture.

i felt half-asleep in my linear algebra course, this morning. i forgot to slow down the computations .. and when i turned around, every so often, to ask if there were questions ..

.. there were students writing furiously.
[sighs]

that's the odd thing:

my numerical computations are faster when i'm not fully awake; there's none of the usual neurosis to slow down the steps for the students ..

sometimes i wonder if my students are aware that ..

• in a lecture, presenting a computation takes at least twice the time it takes to write it down yourself;
• the closer one is to the board, the less one is aware of the big picture. it's much like how close one is to a kitty (xkcd).