http://tokyo3.org/forums/holiday/posts/886392/
Thinking other day, part from young people (toddlers certainly can be an exception) that people sleep so others can sleep/rest. I mean a sober adult of sound mind doesn’t act in a way that might wake (or keep awake) those near. Letting another sleep, like if you have kids you don’t wake them (excepting to go to school or whatever).
So you know like whole towns go quiet of the night to let each other sleep.
In an interesting way letting others sleep can be seen as a task. Maybe seems a stretch to think of being asleep to facilitate sleep/rest for others to be a task, but there’s no reason wakeful(ness) activities need monopolize what is a task.
It can be said to be (part of) whatever function/s.