Matthew Walker

The gross demonstration of caffeine is that it prevents you from falling asleep. The slightly more nefarious aspect of caffeine is that maybe you can fall asleep, but we know that the depth of deep sleep you're getting if caffeine is still in your system is severely less.

Individuals fail to recognise how their perennial state of sleep deficiency has come to compromise their mental aptitude and physical vitality, including the slow accumulation of ill health.

Sleep is the Swiss army knife of health. When sleep is deficient, there is sickness and disease. And when sleep is abundant, there is vitality and health.

Our circadian biology, and the insatiable early-morning demands of a post-industrial way of life, denies us the sleep we vitally need.

I think the first general point to make from epidemiological studies across millions of people is the following - that short sleep predicts a shorter life. It predicts all cause mortality.

We now know that we imprint information during the day. We sort of - that seed is planted there within the brain during the day. In other words, we learn information. But we also know that that vision that was planted in the brain still remains in the sound of silence, in this - in the dark of night.

Dream sleep provides a fascinating neurochemical soothing balm. It is during dream sleep and only during dream sleep when our brain shuts off a stress-related neurochemical called noradrenalin.

Creativity is, after all, lauded as the engine of business innovation.

Your subjective sense of how well you're doing under conditions of sleep deprivation is a miserable predictor of, objectively, how you actually are doing.

The amount of sleep - the total amount of sleep that you get - starts to decrease the older that we get. I think one of the myths out there is that we simply need less sleep as we age, and that's not true, in fact.

Alcohol is a class of drugs that we call 'the sedatives.' And what you're doing is just knocking your brain out. You're not putting it into natural sleep.

I think many people walk through their lives in an under-slept state not realizing it. It's become this new natural baseline.