Sleep

This is my personal experience, so I cannot comment on others. 

Drifting to sleep and not being aware we have done so seems odd.  There is far more to consciousness than we are aware of I think. 

Falling asleep - NOT amateur radio

This is very odd. When you fall asleep, you are not aware of it. At some point you are awake, then you drift off into sleep. Usually I fall asleep quite quickly, whereas at other (rare) times it can be hours.

Getting to sleep - NOT amateur radio

Usually I sleep well, but have you noticed how hard it is to get to sleep when you try to? 

Sleep is odd as you are not aware when you actually drop off: you are awake and then you must be asleep! Waking up very early is very hard.