People are unaware that banks can print money

We can assume that people would not value a currency which can be printed at will by private banks. So then since money is valued in spite of this fact we are able to deduce that people are ignorant of how banking and money works. If people know that banks print a particular form of money then that money would not be valued. People only value money which cannot be printed by banks. If people know about the banking system they will cease to value money. People don't know banks can print money otherwise the money would not be valued.