I mean, you might have noticed, but not any human can perform magic. The natural thing is a bit different, too. I mean, I've seen dad perform spells without incantations before, if they're simple enough, but there's no one special thing anybody can do.
I've also never heard of hex bags or stage magicians using legitimate magic to kill one another.
[Judging by the look on her face, that was the part of the lecture she was least happy about listening to.]