Is everything a reaction?

Is everything a reaction? 

The simple answer for me is yes.  When I wake up I am in a certain mood.  My thoughts about what and how to paint are a reaction to my situational daily condition.  Is it a beautiful day?  I will decide to paint plein air or studio based on the weather.  What color is the sky?  It will help determine what color choices I make in my painting.  The color that I want to paint with helps shape what subject I will be painting.
My reaction keeps shaping decisions to the point where the decisions themselves create smaller reactions like the ripples on the water.  Everything I do during the painting changes everything I do on the painting.
The key for me is keeping true to the main thoughts and decisions so I can stay on track with my original intentions.  When that happens I have what I consider to be a really good painting.