When I used to bike commute to work, I had a similar effect. My commute to work is about 1 hour each way. On the way to work, ideas about work would pop into my brain. On the way home, ideas for home would pop up. Need to say that I don't really think about either work or home, they just pop up.

Sadly that does not occur so much now that I am driving to work. I wonder if cycling vs sitting is the differentiater here.