The first time I can remember succumbing to sleep deprivation symptoms was as a student when, as with many eighteen year olds at the time, the idea of travelling across Europe foot loose and fancy free was a wonderful adventure.
Hitch-hiking was a more accepted way to get across Europe in those days.
Now students are much more likely to suffer another sleep disorder in their sabbatical to Australia or Far East, jet lag.
Very tired But hitch-hiking with your home attached to your back like a snail had a number of down sides.
Trying to sleep in a tent in the Jura Mountains during blizzard conditions was just about impossible.
Eventually after just about reaching Bologna in Italy we decided to turn back and head home to our beds.
Eventually we reached Dover in the early hours of one glorious morning with no sleep in the previous 44 hours and very little for the last five days.
Talking rubbish Over a celebratory "the works" breakfast we tried to analyse how we felt but I can remember the conversation was very strange.
It appeared that one of the sleep deprivation symptoms was an inability to construct sentences that made any sense and concentrating on anything else apart from stuffing our faces with egg and bacon was difficult.
"Over tired" Prior to our sumptuous breakfast we had been trying to get some sleep on the ferry but to our astonishment were unable to relax enough to get any shut-eye.
Later I realised another symptom which was what our mothers used to call being "over tired".
So it seemed like one of the symptoms of sleep deprivation was not being able to sleep.
Hallucinations? It was on the ferry after I realised that the sleep switch was stuck on "off" when I decided just to wallow in a weird state of dream-like wakefulness.
I remember it not being an unpleasant feeling as I thought I was in control of the odd messages that my brain was receiving from my eyes.
It hadn't occurred to me that hallucinations were another of sleep deprivation symptoms until a well rested week or so had passed.
Irritable Looking back on the adventure from a more distant time frame the decision to turn back at Bologna was made as a result of increasing friction between me and my fellow traveller.
An irritability had set in which I later realised had been another symptom of sleep deprivation.
Bad decisions The decision to turn back was a good one and fortunate because it came out of a fog of poorly made ones like the evening we decided to pitch our tent in a field without first assessing the environment.
This was in part due to another fog which was quickly enveloping us but mainly to do with the overwhelming fatigue that we were both experiencing.
Suffice it to say that we awoke earlier than anticipated to the sound of a marauding bull and just about cleared the fence with our dignity.
Lost appetite The years have now dimmed the details of the events of that holiday although some of the highlights and lowlights linger.
I remember crawling out of our tent and struggling to heat up some gruel to eat and set us on our merry way each morning but strangely I don't recall eating anything during the day.
This may be a blurred memory or perhaps our sleep deprived state was again the cause.
It is odd that I can remember the sensation of being tired all the time but don't remember the sensation of hunger until the promise and smell of "the works" at Dover.
Outcome Without reading anything into it, the fact was that my companion ended up going off travelling again and didn't return for 5 years.
I hope it wasn't me! Can be worse Sleep deprivation symptoms had mounted up and that was over a period of just a few days although the lack of sleep was quite extreme.
Over more prolonged periods the effects of sleep deprivation are worse and can have more subtle effects on individuals.
Extreme cases can have devastating effects on everything and everyone around.