Sleep is as critical to our wellbeing as food, water or shelter. Yet, as a society, we don’t always treat it this way. Research shows that Americans lack proper sleep: Most adults function best when they sleep 7-9 hours per night, but over 40% of Americans sleep fewer than 7 hours nightly, according to a recent Gallup poll. 30% of people report difficulty falling and staying asleep at least a few times per month; 6% experience insomnia on a near-nightly basis. This problem has even birthed an entire industry: In 2014, people around the world spent $58 billion on sleep-aids, a figure projected to rise to $76.7 billion by 2019.