Everyone can identify with the heavy eyelids, dry mouth and foggy brain that sets in after a poor night's sleep.
This was a daily reality for me when I suffered from insomnia for months at a time over two years while I was a student at Otago University.
Life in Dunedin meant many hours studying, late nights out with friends, poor diet and very cold students flats.
These factors all contributed to me sleeping two hours a night for months.
The strangest thing for me was I never felt sleepy or drowsy during the day, in fact I experienced the opposite reaction.
I was operating with very little sleep, so my body was producing a lot of adrenalin to keep me going, which made the problem grow into full-blown insomnia.
I became irritable, hyper-active, unable to concentrate, and very fidgety.
At my worst, I would imagine people were following me when I was walking home from class.
Finally, after seeing a number of doctors, I was referred to Dr Alex Bartle, the sleep specialist.
Dr Bartle taught me the basic principles of "sleep hygiene", a routine that promotes a good night's sleep, and very quickly everything turned around.
I could sleep for six hours straight, and would wake up feeling like a completely different person.
My flatmates told me I had stopped being such a nightmare to live with, and my grades improved.
I still keep up the "sleep hygiene" routine, and have found the rule of no computer or cellphone screens an hour before bed the most beneficial.
Suffering from a sleep disorder at some point in life is incredibly common.