Sleepless night

At night I do all sorts of things. In my dreams I used to practise learning language, because in my dreams, there always was someone with endless patience listening. In my dreams I would practise an exercise in Maths that I didn't get immediately. In my dreams I learned. Today, I cannot sleep. What drives the drive to accelerate at times, or slow down at others? I think in the middle of the night of those who suffer just knowing it can help that someone pays attention, in a dream or outside of it all.