Don't think for a moment that the human brain is simple. It would certainly be nice if there was one on switch for awake and one off switch for sleep. As I have already explained you have a sleep department and a wakefulness department residing within your hypothalamus gland. The new science shows that you also have an arousal thermostat in your hypothalamus gland that has a huge impact on your sleep. It is not residing in your wakefulness department, but operating alongside.

If this arousal thermostat is set too high then your nerves will be too stimulated, as if in a fight or flight state, and sleep will be difficult. It has now ...