You're still exchanging a significant fraction of your house air every day. (pale_chartreuse can probably speak to this more knowledgeably.) Leaks around outlets and light sockets, unsealed windows and doors, air flow up through the attic and out, even through the walls--unless you have a perfect vapor barrier around your house, which given its age I doubt.

I'm sorry to hear about the pains in all the diodes down your right side. Do you sleep funny? Or mouse funny? Or store stress asymmetrically?