If you’re a fan of this website, you understand that sleep is a fascinating topic and there’s a lot to talk about. Over the next 11 weeks, we’ll show you just how much, with a series of weekly infographics featuring a whopping 80 facts about sleep. This first graphic demonstrates just how much sleep knowledge has changed over the last few thousand years. Over the last decade, we’ve seen great leaps in our understanding of sleep, but what was different hundreds or even thousands of years ago?