User blog comment:Demon Killer/Sonic Reboot Idea/@comment-17720060-20110903211951/@comment-10603955-20110903215140

Well actually, he has to get it from somewhere. You can't be just born with it. You must have something to enspire you to do something, you don't just do it for no reason.

Sonic Underground actually explored this (though it was non-canon).