What does it mean when you wake up and your neck hurts really bad when you turn it?

It means your normal slight neck is not changed

It settles nerves, reduces the tension.

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle