Despite sleep being everywhere we all do it and we all talk about the amount of hours we caught last night - none of us seem to get enough of the stuff for ourselves.
Adults are recommended to sleep for seven to eight hours every night, and yet almost half of us average under six hours, according to a survey carried out by the Sleep Council in 2011.
There are two common complaints that explain this deficit: 1) there simply isn't enough time in the day to get everything done, and 2) that a 'racing mind' at night keeps us awake, biting into our quota of daily shut-eye.
The second of these factors props up an entire industry. Sleep trackers, sleep-improving beds, sleeping pills, clinical sleep diagnostic devices, sleep consultants: in the US alone, it was estimated that $32.4 billion was spent in 2013 on things that help us get some kip.
But before you go splashing the cash, it's worth bearing in mind that there are simple tips and tricks that can help you fall asleep quickly for free.
1. The 4-7-8 technique
Pioneered by Harvard-trained holistic health doctor Andrew Weil, the 4-7-8 technique is as gloriously simple as tricks to make your body fall asleep come.
All you have to do is lightly touch the ridge of tissue behind your top front teeth with your tongue, exhale completely, and then adopt the following breathing pattern:
Breathe in through your nose quietly for a count of 4
Hold your breath for a count of seven
Blow air out through your mouth for a count of 8, making a 'whoosh' sound
Repeat the process three more times
Dr. Weil says the technique is a powerful method of falling asleep because it delivers more oxygen than normal breathing to the parasympathetic nervous system, which becomes over stimulated during times of stress.
Regular counting also helps to distract the mind from the issues of the day that it can carry to bed.
2. Turn off the heating and use a hot water bottle
Ever wake up in the middle of the night feeling cold? You've probably put it down to a drop in temperature outside - but the real reason is often a drop in temperature on the inside. Your inside, to be exact.
Every night, as the body falls asleep and its systems switch to standby, its core temperature drops. Think of it as akin to a car that's been parked up on a driveway after a 100 mile journey.
By preparing a sleep environment that's around the 18 degree mark, you'll help your body's core temperature quickly and naturally reduce, which in turn creates the effect of drowsiness.
And while it may sound counter-intuitive, a hot water bottle can actually help the process. Place the warm rubber container next to your feet. The heat will rapidly dilate blood vessels in your lower limbs, helping the body to redistribute heat from your core to your extremities.
3. Ban all electronic devices from your bedroom
As anyone who works overnight shifts will testify, going to sleep during the day can be difficult even after years of training.
That's because light plays such a forceful role in our sleeping patterns. The key here is the hormone melatonin, which is produced by the pineal gland and appears to facilitate sleepiness.
Melatonin is only excreted into our blood flow when there is little light in the surrounding environment; a natural or artificial light source halts its production and potentially keeps us awake.
Banning smartphones, tablets, and even bright electronic alarm clocks from your bedside table will help you enjoy bask in a sleepy haze of melatonin at nighttime.
It will also mean that you can't pick up or respond to that stress-inducing email from your boss at five minutes to midnight.
4. Learn to sleep like a yogi
In yoga, a practice known as yoga nidra is designed to pull you down into the deepest state of relaxation while remaining fully conscious.
However, as the technique requires you to lie completely still while calming your mind and relaxing your muscles, it's easy to adapt for the insomniac who wants to fall asleep.
Fundamentally, yoga nidra involves systematically switching your attention around the parts of your body. You start at your finger tips and travel slowly up your arm, into your torso, and then down one side of your body into your toes, before repeating the process on the other half.
Anyone who is still awake by the end can then use their exhalations to count down from 40 (inhale, exhale, 40, inhale, exhale, 39, inhale, exhale, 38, etc).
There are plenty of guided tutorials on YouTube to help newcomers get the idea.
5. Learn to sleep like a ninja yogi
A variation on the method described above, this involves tightly clenching individual muscles in your body. After squeezing, say, your bicep as tightly as possible, you release the slack and feel relaxation flow into the muscle fibres.
Try not to move the muscle thereafter; instead, think of it as being 'asleep'.
A great relaxation technique - and a mini workout too.
6. Use a pillow
You probably know by now that falling asleep at night is all about feeling comfortable and relaxed.
And you probably know by now that you're supposed to use a pillow when you get in bed.
What you might not know, however, is where. While there is little evidence to suggest that using a pillow to elevate your head offers universal benefits (it's mainly a matter of personal comfort), there is a school of thought that suggests they should be deployed for other parts of your body.
For example, when lying on your back, try placing a pillow beneath your knees. This will allow your lower back to assume its natural curve and relax into the mattress, rather than arching up like a suspension bridge.
Or, when lying on your side, consider popping a pillow between your legs. This will stop the higher leg from pulling around, putting stress on the spine and hip.
7. Push your own buttons
A traditional Chinese cure for insomnia is acupressure, which is a bit like acupuncture except without the needles. All you have to do is apply pressure to the specific parts of the body that are believed to promote sleep when touched.
Press and then massage a few select areas of the body, including the indent between the top of your nose and your eyebrows, and the point just beneath the ball of the feet.
8. Try staying awake
Research conducted on two groups of insomniacs at the University of Glasgow found that reverse psychology can genuinely help people fall asleep.
While one group was left to their own devices, the other was told to stay awake for as long as possible but banned from moving around or watching TV.
Guess who went to sleep fastest?