Thinking

Woke up early thinking.  Don't know why, don't remember what I was thinking about.  I was just awake and couldn't get back to sleep.  Did the body inventory to see if anything hurt or was awkardly arranged.... the dogs weren't up and they didn't notice I was awake.  My mind was active, so I tried to calm that.  Breathing in I notice my breath, breathing out I notice my breath... and fell back asleep for a couple of minutes.  So, then the mental inventory... am I worried about something I need to do today, did I forget to do something important yesterday, is there someone I need to talk with about something?
No clue.  So, I accepted that I was awake, thinking randomly and that allowed me to go back to sleep.  I have no idea how this works....