I am tired. I am so very tired. And so I’ve been thinking about tiredness. And somewhere in the middle of the night, I got to categorising tiredness. (My usual trick for getting myself back to sleep – working my way through the alphabet and thinking of a character from The Archers for each letter – hadn’t worked, and I’d done it twice. Which gets tricky with the Ns. I could only think of Nic so I had to resurrect Nigel.)

Here’s what I got:

1. Physical tiredness. The tiredness that you get after a good long stint of walking, or gardening, or running a marathon. (The last two are assumptions on my part. The most I ever do in the garden is a little bit of planting and, later, wandering around to see how everything is growing. I like to think that Alan enjoys weeding. And I’ve never run a marathon, as you’ll realise if you’ve been at Bah! for more than about 15 seconds.)

2. Mental tiredness. The feeling that comes after a period of intense concentration, whether it’s writing, driving, meeting new people.

3. Emotional tiredness. Tiredness born of grief, worry, anxiety.

4. Own-worst-enemy tiredness. Tiredness that comes from staying up too late, having a glass of wine too many, putting too much in the diary. I do this more often than I care to admit, on the days when I forget that I’m not 25 any more.

5. Travel tiredness. Which I really, really don’t understand. I went to London last week: three and a half hours there, knitting and watching ‘Grey’s Anatomy’, three and a half hours back, reading and drinking coffee. How is that exhausting? But it is.

6. Ill tiredness. The body is very clever at making us tired when we need to heal. Even cleverer, it makes the brain foggy too, so being ill-and-tired is, if not pleasant, at least straightforward. Cancer eventually taught me the wisdom of being able to recognise this tiredness and, if not embracing it, understanding the purpose of it, and getting some easy knitting out with the semblance of good grace.

7. Excited tiredness. That Christmas-Eve feeling, as you wait for news or a birth or some sort of a Big Day to come around.

8. Chronic tiredness. This comes from chronic illness, chronic pain, and I imagine – from my periods of short-term chronic pain (if there is such a thing) that it becomes like a weight that you forget is there: like forgetting that your shoes are too-tight until you take them off. Except you don’t get to take them off.

9. Tiredness in and of itself. Some people just don’t/can’t sleep. This is my idea of hell.

10. Tiredness from chemically-induced sleep. I occasionally take sleeping tablets, and the sleep that comes from them is both solid and unsatisfying: I feel as though someone has switched me off, then switched me on again, only pausing to spray the inside of my mouth with essence of dead gerbil before they do so. And I still feel tired. So, not my preferred option, but needs must, sometimes.

I think, at the moment, I’m suffering from a combination of sleeplessness brought on by 3,5,6 and 7. So I’m resigning myself to a couple of nights of 10…. unless anyone has any better ideas?