How do you sleep? We getting told we need "full 8 hours", but where does that phrase come from?We're constantly being given advice on how to sleep, apps are geared to "unwind" our minds, you can buy countless books about how to be a more rested you. But we don't always interrogate that advice or look at how our ancestors behaved. Professor Roger Ekirch is a historian at the Virginia Tech. He has spent decades looking at the accepted history of sleep trying to understand how our ancestors slept, and how they viewed the concept of rest.