Painting In One Hour Stints

Yesterday a friend asked me how I decide what to paint.  I didn't really know what to tell her. Do these images really just come to me?  Are simply the result of the casual image logs I make through my bias filter throughout a day?  Is there something I want to say and therefore come up with an image? 
I think that it has been the latter for me at times; in my political and suicide paintings I used that format pretty directly.  The past several years for me though, ideas and images have seemed to form more closely together making It increasingly difficult to tease apart, and answer questions about my decision making.
My most recent work (shown here and in progress) is the closest piece to contain more of a  separation between idea and image than any of my work over the past several years.

I don't know what comes first but goes something like:
Idea: How do I feel in this space?
Image: Still life of anything for a pink color study.
Idea: This is a special place that should be recorded.
Image: Cathedral ceiling surrounded in pink.
Idea: The transition of a space from Nana's home to my studio to Kevin's home.
Image: Contrasting styles and patters and emphasis on color transitions.

My studio rhythm reflects this back and forth.  I usually paint for about 45minutes to an hour and then spend about 20-30minutes looking at the piece while allowing myself flip back and forth between my questions and concerns about what is going on.

So still, I have no answer for my friend and I guess that is fine, but I would really like to work that out so that I can have a more fruitful conversation about this with my students.