Those who believed the Earth revolved around the Sun were once considered mentally ill.

It was only after their deaths that people started to realise. What seemed obvious to those who knew, was strange and insane to those who couldn't understand. Especially those who clung on to the comfort of the universe revolving around God's world.

It was just better to believe in the fiction of the Catholic Church at the time than the reality. The reality threw up questions, while the fiction was comforting.