Parents of small children tend to be very careful about bedtimes.

They favor early nights, they give their babies plenty of naps throughout the day, they think a lot about black-out curtains, they are quick to diagnose many instances of bad temper as stemming from a background deficit of rest.

And while they may be indulgent in some areas, they are likely to be entirely implacable in any negotiation over routines: seven p.m. lights out, no ifs, ands or buts.

None of this is remotely altruistic: tired small children are a nightmare to look after.

Every reversal becomes a drama, every disappointment turns into a catastrophe, and every excitement shifts into mania.

A half-way decent adult existence is impossible alongside a tired child.

Self-interest necessitates totalitarianism.

But while a draconian philosophy is useful in the early years, it can set up an awkward dynamic in an off-spring's mind as adolescence sets in.

Growing up and asserting one's independence and individuality can then become associated with a newly defiant and cavalier approach to bedtimes.

Not for the newly empowered young adult, the strictures and denying rules of the past.

Why bother to put the light out by ten, or even midnight or one in the morning, given that one is so obviously no longer a toddler?

What is thereby missed is how much every adult shares in a young child's sensitivity to a shortfall of sleep.

Just like our younger selves, we do not have an impregnable command over a reasonable view of our own prospects or condition.

There are many different ways of telling the story of our lives, ranging from an optimistic tale of progress mixed with noble defeats, to a tragic narrative of thorough-going stupidity and unforgivable errors.

What can determine the difference between madness and sanity may be nothing grander, but then again nothing more critical, than how long our minds have been allowed to lie on a pillow in the preceding hours.

It's especially unfortunate that this connection is so easy to miss.

No bells go off in our minds warning us that we are running low on nocturnal nectar.

As a result, we start to believe many dark things with doomful ease: that our relationship is over, that everyone hates us, that our lives are meaningless and that human existence is a cosmic joke.

'When we are tired, we are attacked by ideas we conquered long ago,' knew Friedrich Nietzsche.

We go mad from tiredness long before we notice the role of exhaustion in stealing our sanity.

The thinking we do when tired is vindictive and sloppy.

It misses important details, it gives the advantage over to our enemies, it hands victory to the evangelists of sadness.

Being careful doesn't just apply to the night.

At varied points in the day, when possible and we are overwhelmed, we should know to stop, hoist the white flag and have a nap.

When we lie in bed, it makes sense to think of ourselves as akin to a smaller, furry mammal, a rabbit or perhaps a squirrel.

We should lift our knees up very close to our chests and pull the duvet over our heads.

We might soak a whole patch of the pillow with our tears.

We should—metaphorically—stroke our own weary foreheads as a loving adult might once have done.

Grown-up life is intolerably hard and we should be allowed to know and lament this.

We shouldn't feel weird in our weepy squirrel position.

Other people go to immense lengths to hide that they do, or would like to do, the very same sort of thing.

We need to know someone extremely well—better than we know 99% of humanity—before they will let us in on the scale of their despair and anxiety and their longings for a cozy, safe nook.

It looks child-like but it is in fact the essence of adulthood to recognize, and give space for, one's regressive tendencies.

What the curled squirrel position indicates is that not all mental problems can be solved by active reasoning. Not thinking consciously should also be deemed a part of the mind's work.

Being curled up in bed allows our minds to do a different sort of thinking, the sort that can take place when we are no longer impatiently looking for results, when the usual hectoring conscious self takes a break and lets the mind do what it will for a time.

It is then, paradoxically, that certain richer, more creative ideas can have the peace and freedom to coalesce—as they may do when we are out for a walk in the countryside or idling while having a drink in a café.

Thinking isn't what we do best when it's all we're meant to do.

There remain plenty of reasons to live.

We simply may not be able to see them until we have allowed ourselves the privilege of a weepy nap or a long night's sleep.

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