As Sir82 says, "Clearly, breathing is of pagan origin." It would seem that most everything is of pagan origin.
Watchtower picks things to be against, mostly based on how it will make members uncomfortable around worldly people, particularly family, coworkers, and schoolmates.
Weddings bring JW's together and offer opportunities to show worldly family that they are almost normal, but birthday cakes cause coworkers, schoolmates, and worldly family to show their friendly good side, so Watchtower poisons it. Similar with holiday celebrations. But wedding rings are a protection (or at least used to be) from outsider advances.