If you think your body goes through different changes throughout the day spare a thought for the brain. The brain is driving all the functions and is quite often on auto-pilot so you can carry on with other functions. Wow! There is a lot going on in our heads. Simply put, we never stop, we just change gears throughout the day and night. Not surprisingly there is often a rhythm and harmony that is created that we grow comfortable with.
Quite often our lifestyles dictate that we have to follow a rhythm to work or do some meaningful actions. It gives us purpose, an importance and an identity and sometimes our brain just simply loves being busy. We feel in harmony when we know what ourselves or others are doing.