Research has shown that a third of one's life is spent asleep. Another third is spent feeling like it would be nice to go back to bed. The final third is spent hoping that it will soon be time to go to bed. Feeling tired is like being up and about but still having your brain under the duvet. People who do the least get the most tired. Teenagers often have to go back to bed to cope with the exhaustion brought on by the trauma of getting up. When you're really tired, even the thought of doing something is exhausting. In fact, doing something is generally less tiring than thinking about doing something.
Smiling is supposed to be good for you because it exercises many of the facial muscles. On the other hand, trying to keep your eyes open when you're exhausted uses every single one of the facial muscles, which is why it's impossible to smile at the same time. No surprise then that the first casualty of tiredness is charm. There's no such thing as an insomniac charmer. As you get more and more tired, you can't say anything charming, then you can't say anything interesting, then anything nice, followed by anything intelligible, and finally anything at all because if you moved your mouth your eyes would close.
There is a phrase which says that when you're tired of London you're tired of life. This explains why people on the underground generally look suicidal. There's another phrase,'Tired of Swindon, get a life', but that's slightly different. They also say 'early to bed, early to rise, makes you healthy, wealthy and wise' - hence the national glut of rich philosopher-milkmen. A better phrase would be the complete opposite: 'late to bed, late to rise, makes you unhealthy, poor and stupid'. It won't be long before beds carry a government health warning- 'Sleeping in Kills'. A nasty condition some people suffer from is when you get too tired to sleep. This is where the whole business of putting your head on the pillow and falling asleep is just too much effort to go through with. Equally nasty is feeling tired when you get up in the morning. This is like feeling dirty when you get out of the shower: you feel well and truly cheated. Some people can catnap for ten minutes and then carry on as fresh as a daisy. For most normal people, having a nap is like a tiredness enhancer. You get fleeting pleasure from falling asleep, but then you wake up three hours later with a hangover, cramp, dry mouth, dead leg, gummy eye, leaving your partner there, wondering if you're dead.