Then there are our drugs of choice: “Caffeine consumption is obviously up. Caffeine is the second most traded commodity on the surface of the planet, would you believe, after oil, which tells you everything about the state of our sleep-deprived society. If there was a commercial metric of how sleep-deprived we are, it is probably that. Caffeine keeps us awake, it makes it harder to fall asleep, we all know that, but some people might not know caffeine also prevents you from getting good, deep sleep. So someone might say to me, 'I’m just one of those people who can have a coffee after dinner and I’m fine, I fall asleep and it’s no problem'. The problem is that even if you fall asleep, the depth of your sleep won’t be as deep as if you had abstained from coffee.”