Duff, for those you woefully ignorant of its meaning, is all that stuff on the forest floor – dead plant material, leaves and bits of bark and needles and twigs, that has fallen to the ground and lies there, rotting, rotting. As it rots it is enmingled with the top layer of soil and this is what scientists call the O horizon. I am not a scientist, so I stick to duff.

Some would have you believe that the duffle or duffel coat is so called because it is made from coarse thick woollen material originally made in the Belgian town of Duffel. Likewise the duffle or duffel bag. Although this is almost certainly true, and not really open to doubt, we should not overlook the fact that long long long ago, primitive shambling savages lumbering about the primeval forests fashioned for themselves clothing and bags made from the duff on the forest floor, thus duff coats and duff bags, easily tweaked to become duffel or duffle by the vagaries of human speech.

Of course, it was all so long ago that no one living has ever seen a primitive shambling savage making a coat or bag out of duff. Intuitively, one might think the thing would simply fall apart. Perhaps when first gathered up from the forest floor, the duff would be wet and sticky and thus hold together. But time, heat, drying out, and certain exertions on the part of the savage would surely make a duff coat fall to bits soon enough. And one wonders what could possibly be carried in a duff bag without it, too, being rendered useless.

Clearly, then, our primitive shambling savage forest-dwelling ancestors must have devised a method of strengthening the matted duff. They may have used rudimentary needlework, or perhaps a type of glue or gum. The best way to find out was to conduct an experiment. That is why I had myself parachuted, stark naked, into a forest. I should point out that the parachute was made of tough synthetic twenty-first century fabric, not from duff. I have never argued that primitive shambling savages made duff parachutes, so I was not being inconsistent. Once I had landed, high in some tree cover, I unhitched myself from my harness and clambered down to ground level. I had made an appointment to meet up with my research team in twenty-four hours time, in the Cow & Pins, a somewhat insalubrious tavern on the edge of the forest.

Standing naked and alone in the dark dense forest, I found it easy to imagine myself a primitive shambling savage in the dim and distant past. I grunted a few times. I spotted a tiny wriggling creepy crawly on the trunk of a tree and plucked it off and popped it into my mouth and chewed it and swallowed it. It tasted foul. I began to feel like a monkey. The strange thing is that within five minutes of landing in the forest I had actually become primitive and shambling and savage. I quite forgot about my appointment. I forgot about my everyday life. I forgot language. I grunted and scratched and ate creepy crawlies.

I might be there still had I not taken the precaution of carrying, on a lanyard around my neck, a pochette containing a portable metal tapping machine. It buzzed and beeped and I took it out and held it in front of me, wonderingly, as if it were a magic box, which, in some ways, it is.

“Calling Mr Key! Calling Mr Key!”

In my primitive shambling savage state, I was so surprised at the voice issuing from the magic box that I dropped it in the duff. The voice grew more urgent, until I picked it up and grunted at it.

“Ah, you’re there, safely landed I assume?”

My brain was a chaos, but suddenly I remembered everything. There was a bitter taste in my mouth.

“Ack!” I spat, “I’ve been eating creepy crawlies plucked from tree trunks!” I cried.

“Well there’s no time for that. You have twenty-three and a half hours until you are to meet us in the Cow & Pins, in your duff coat, with your duff bag. Get cracking! Over and out.”

Next time I conduct an experiment I must remember to appoint a less peremptory research team.

I do not wish to get bogged down in the detail of how I spent the next several hours. Let me confess that more than once I prayed to high heaven, wishing I were in a provincial town in Belgium rather than in the dark dense forest. It is not being melodramatic to say that I knew, more fully than ever before, despair. I wept. I howled. I scrabbled in the duff – duff that, far from being wet and sticky and holding together at least for a few minutes, as I had imagined, was bone dry and frangible and fell through my fingers even as I picked it up from the forest floor.

Do you have any idea how damnably difficult it is to stick one tiny fragment of duff to another tiny fragment of duff using only some goo that you find smeared here and there on trees and leaves? How tiresome it is when you have used up all the available goo and have to go plodding off to find more? How in dragging with you your patiently-stuck-together duff-fragments they snag on a stray twig and become unstuck and fall apart so you have to begin all over again? How the occasional roar of Sabretooth jet fighters screaming across the sky over the forest jangles your nerves and makes you a butterfingers?

With twenty minutes to spare, I trudged into the saloon bar of the Cow & Pins to greet my research team. I was dressed in a fetching duff coat and duff pantaloons, with a duff cap on my head and duff socks on my feet. I had a duff bag slung over my shoulder, empty, because it was too weak to carry any weight.

“Mission accomplished!” I yelled.

In the corner of the pub, there was a gang of scientists sat around a table.

“Look!”, one piped up, “The O horizon!”

And they sprang up from their chairs and picked me up and carried me off to their science van and drove me to their lab, where I have languished ever since, prodded and probed and poked at, and fed, now and then, on bitter, bitter creepy crawlies.