Many spells of old work backwards when stolen. This was the way of protecting secrets. This why we have special names for herbs and sometimes odd words for things or code. We had to protect information from the general public. Knowledge shared is power lost.
Power needs to stay with the witch the wizard and the coven.
General Knowledge should be given to the child so that new secrets can be made. We all Have secrets. We all hold them dear like a baby in a winter's breeze. Some will tell you that it is OK to steal. It is not.