The ethymological and unanswered question about how how we got from the bowl to the head reminds of the legend of Vikings using their ennemie's skulls as drinking bowl.
I found reference to this being a myth but to the allegation that it was the practice of nomad tribes of German origin.
This would lead me to think that the mazard (skull) use as a mazard (drinking bowl) is not that far fetched.
Ahh, the good old days when thinks were simple and recycling commonplace smile
Have a happy new year.