Ha haaa, I never put much thought into this marvelous theory. Until now. I think you are onto something with this bum-brain connection. I can only really write at my nice desk chair with odd keyboard. (Could be hands as well as buns there). But the ideas seem to come more fast and furious there, vs. other areas of sit.
And it really comes to play in the TV and eating thing. Though, I usually DO remember what I got up for, and that is worse. Then I don't get any exercise bopping back and forth like you. And I just get a cart, set up shop, and sit until the bum goes dead to the world. Then NOTHING happens. Except the south end just shouts, "to the larder". Large sigh.
Shower is the best thinking area, so that is not the butt. But you can't snack efficiently in the shower, so it's not as much fun. Maybe I should try a bath, then I could snack AND think more. Since my bum is on the hard tub. Wow, you've started all KINDS of thoughts here. And I need to get to my next post. Yikes.
I thoroughly enjoyed your write/mic here. I'd say don't quit, keep them coming. Very funny indeed. And thought provoking. Have a nice day.