Often I have to explain to people that no, people in medieval age didn't die when they were 25, that life expectancy is just an average, and thus it averages ou

Often I have to explain to people that no, people in medieval age didn't die when they were 25, that life expectancy is just an average, and thus it averages out people that lived normal lives (ie: plenty of people died in their 90s, as do people today) and people that died really, really fast (childbirth, child accidents and wars are particularly good at skewing the data). Another one is trying to explain that people knew Earth was round for a looooong time. Also explaining that no, Greeks didn't really believe Atlantis existed... our earliest record of Atlantis was Plato mentioning the myth... so even to ancient Greeks, Atlantis was a myth already.