Come to think of it I'm now curious how this is possible. With cracking open bottle tops, it is all leverage (not strength, power, or some physical gift) but I

Come to think of it I'm now curious how this is possible. With cracking open bottle tops, it is all leverage (not strength, power, or some physical gift) but I would think chewing glass has got to be some special type of skill or physical ability. I didn't have a curious mind for it then since I didn't think it was a special skill although I did not dare try it as it seemed to me as dangerous as it sounded