Every few minutes the wretched thing works loose.

In darkness and in misery, you struggle to get your head out of a clammy towel that clings to you almost with passion.

Brain power is wasted in inventing names for that towel--names expressive of your feelings with regard to it.

Further time is taken up before the glass, fixing the thing afresh.
You return to your books in the wrong temper, the water trickles down your nose, runs in rivulets down your back.

Until you have finally flung the towel out of the window and rubbed yourself dry, work is impossible.
The strong tea always gave me indigestion, and made me sleepy.