I was replete. Lounging, indeed slouching in an armchair after having been fed superbly well by Adam Smith, Game & Wildlife Conservation Trust director for Scotland and his wife, Anne. Having a slightly runny nose, I reached into my pocket for a handkerchief, and felt the usual Opinel pocketknife there.

Nothing unusual in that, you might say, and you would be right. I rarely leave the house without a penknife. The habit of always carrying a simple folding knife was instilled into me by my grandfather. He had a knife for each pair of trousers, and Granny Swan would have been reprimanded if she did not put the knife back where it belonged after doing the washing.

A close shave with security

But I was in Scotland on business, and had therefore smuggled the little knife on to the aeroplane in Southampton earlier that day. So much for airport security, but then the full gravity of what I had avoided hit home. Imagine the fuss if they had picked up the presence of the knife as I walked through the scanner, hands in pockets to hold up my trousers, as my belt has a large metal buckle. I would surely have been assumed to be a terrorist intending to cause mayhem, rather than a forgetful old fool.

The knife taboo

I also reflected on the way in which man?s oldest tool has been gradually demonised during my lifetime. In the 1960s and ?70s, when I was at school, I always had my knife with me ? apart from anything else, I could then sharpen my pencil whenever I wanted. I assume that if I allowed my boys to take a knife to school today, I?d be called up before the headmistress. However, just as with guns, the majority of us use our knives for perfectly innocent and harmless purposes. Danger is in the operator, not the tool.

The last time I had tried to smuggle a knife on to a plane was in the early 1980s. I was off to Belfast for the Northern Ireland game fair, and security was a body search rather than a scanner. The chap who searched me said, ?I had better have a look at your pocketknife, sir,? as he ran his hand down the outside of my right thigh. ?Sorry, can?t let you take that on, sir,? he said, ?it will have to go in your hold baggage.? I had only a briefcase and no hold baggage, so they started to label up a large jiffy bag to take my little knife. While they did that I put my hands into my jacket pockets and found another, so I gave them that too, much to the shock of the guard who had missed it! However, there was no sense of outrage or accusation about my actions. I was clearly just a normal country bumpkin who was innocent enough not to think to leave his knife at home when flying.

Knives are very important to me, and I like good ones. Notwithstanding the cheap old Opinel, which is just right for all sorts of things as well as cutting, a knife that will not take a decent edge is not much use. If you have to force it because it is blunt, you are in more danger of injuring either yourself or a bystander. So, I have a nice sharp little sheath knife for gralloching deer. It has just a short, thin, and narrow carbon steel blade, and was made for me by my old chum Chris Cheeseman. For the house, for both fishmongery and butchery I have a set from the Billingsgate Seafood School in a canvas knife roll.

The sharpest knife in the drawer

At home, the boys know that they are my knives, and not to be touched without permission. They are the first thing I pack when we go on holiday, too. Self-catering accommodation never has good knives. But imagine the consternation of successfully catching a good fish, or bagging a goose, at the start of a holiday, and not being able to dress it properly for lack of decent tools. I once had a bit of fun with the landlord when staying in a farm cottage. He rears top-quality livestock, and saw the knife roll as I was unloading it from the car. When he asked what it was, I said, ?My knives, because none of yours are much cop, and I might need to butcher something while I?m here.? He looked a little worried, but actually he knew I would be hoping for fish or fowl.

The knife roll brings happy memories every time I open it. As I touch a blade up on the steel I reminisce about sporting days. Also, I remember my father as the collection includes one or two old knives that I inherited from him, including a small one he made as a teenager in the 1930s. He used it to earn pocket money by dressing rabbits for squeamish neighbours ? they existed even way back then.