What does it mean that human beings can’t find their “off switch”

That can be taken many different ways maybe: they push themselves to hard and don’t know when to take a break or they cant settle down, sleep or, don’t know when to stop.

It most likely means that there mind cannot or won't shut off and they can't really go into an unconscious state(sleep) and stay awake.

Ibelieve this would be an obstacle.

What do you mean exactly