Our lives aren’t geared particularly well towards sleep, despite the fact that it’s absolutely essential. Most toddlers need around 13 hours, including a daytime nap, but good luck trying to convince them of that. (I’m in Tuscany with 5 kids aged between 20 months & 7 years… I know of which I speak!!). Teenagers need around nine and a half hours, but their ‘ideal’ circadian rhythm means that they prefer to stay up late, which you wouldn’t call ideal when they’re rising early for school the next morning.
As adults we all have our “chosen level of uncomfortableness” in terms of lack of sleep, but that doesn’t necessarily mean we’re okay, says sleep scientist Elizabeth Klerman. Many people convince themselves that they can get by on five to six hours of sleep per night. But ‘getting by’ is a gross understatement when you consider what the research tells us about the impact of sleep deprivation.
Harvard neurologist and sleep medicine physician Josna Adusumilli says that getting six hours of sleep a night over twelve days has a significant impact on cognitive and physical performance, to the extent that performance becomes like that of someone who has been awake for twenty-four hours straight (which happens to be like that of someone who has been drinking). American physician and sleep researcher Charles Czeisler found that we usually only notice any impact of sleep deprivation on performance for the first one or two days. After that it becomes our slightly less sparkly, less effective, new ‘normal’.
We need sleep because it keeps our minds and our bodies in working order. When we sleep our brains do some very necessary ‘housekeeping’ such as processing and consolidating new memories and helping us deal with memories of bad experiences. Being tired also makes it harder to be happy by making it easier to recall bad memories over good ones.
We also need sleep so that our minds can go on adventures in the form of dreams. Freud’s theory was that dreams help us deal unconsciously with problems the conscious mind can't deal with. This might go some way to explaining why people who are sleep derived experience hallucinations.
It seems that sleep is a constant battle in the modern world. We’re either trying to get more of it, or complaining about not getting enough of it and suffering the consequences. Either way, we’re the only ones that can do it; we can’t delegate it to someone else.