Adding in my go-to's, lead was completely safe, until it wasn't; asbestos was completely safe, until it wasn't; cigarettes, cigars, and smoking were completely safe, until they weren't. It goes on forever as people in power tried to force their belief systems onto everyone else, and questioning their power was stylized as insanity and incompetence.

What an awful existence it is trying to fight against this tide of continuously brand-new-to-the-debate people.