Ignorance breeds ignorance can be simply explained through this example..When a radio deejay saying something out of ignorance, and the audience or listeners accepts blindly whatever was being uttered, with the mass mentality that deejay knows best, and later the listeners spread the ideas to their friends.
The more you know the more the world opens up before you, and you understand there is more to know and understand. It seems that truly knowledgeable people come across as humble. Ignorant people mistakingly think that their knowledge is complete and thus come across as confident. Their ignorance breeds confidence.