

Got a concussion in a pillow fight. I was in the top bunk in a lean-to at summer camp when I was maybe 13 or 14. Forgetting the low ceiling above me, I jumped to my feet, planning on launching a pillow at someone poking around another bed. Promptly slammed my head into the ceiling, knocked myself out and wound up going to the doctor shortly after. Pretty sure I still have a disc somewhere with images of the small minor brain bleeding I got as a result.
While Catholics do have a lot of wacky beliefs, papal infallibility is somewhat more limited than this. It only applies when the pope makes an ex cathedra statement, so he would have to state this in a much more specific and formal manner to be considered undisputable doctrine.