In my everyday life, I am forced to remain highly analytic and mostly linear in thinking. I am also forced to be cautious, safe, and take "do no harm" approach. I am also needing to look at the "big picture" and proceed accordingly. Once I'm in my darkroom, all that goes out the window - or I try to think as differently as I can. Behind the camera, since I'm mostly out in public, this kind of thing is not always possible.
Is it relaxing? NO. Is it refreshing? Often, YES. Is it therapeutic? I'm not sure about that one. I do enjoy using "the other side" of my brain though.
Concerning supportive significant other, I fully agree. I am lucky in that regard myself. We just need to remember to enthusiastically return the favor and support her interests as well.