I appear to have made a mistake. I have gone to a climbing wall for our son’s ninth birthday and have worn some old climbing shoes, because I once went climbing in the Lake District with a friend who lent me the footwear.

This is a mistake for two reasons. The first is that our guides at the Climbing Barn think that because I own a pair of climbing shoes, I have previous experience in climbing. I try to explain to Gaz and Clive that I went once, about 15 years ago, and I was so scared I practically ran vertically up the cliff-face, a bit like Road Runner in the old cartoons.

The second reason it is a mistake is that my footwear is causing hilarity. Clive suggests that I take the boots to the next Antiques Roadshow, calling Gaz over so the pair of them can stare in amazement at my ancient climbing shoes, pondering between themselves when the company that made them actually stopped manufacturing such things. Between eight and ten years ago, is their estimate.

My protestations that I have had practically no experience in climbing doesn’t seem to cut much ice with Clive and Gaz. While Gaz takes the children to one side, Clive takes the adults and points at a rope that goes to a point high above us, about as tall as a house. There seems to be some mistake.

The one thing I remember about climbing in the open air is that half-way up I sat on a saddle of rock and looked out across a plunging Cumbrian valley, and got The Fear. It just felt too high up. I thought I might have to stay there until a helicopter came to get me, but thankfully my friend Tim managed to persuade me – I think there might have been the promise of a pint involved – to get my backside moving.

As I start to haul myself up the climbing wall I get the same weird feeling in the pit of my stomach. But I just focus on the wall and before I know it I’m up in the rafters, glancing down and grinning. I’ve done it.

My wife seems to have no such compunctions as me, and clambers up the wall next with no problems. But she’s always been the athletic type, while I’ve always been the lie on the sofa with a king-size Toblerone type.

The next day I e-mail Tim to tell him that we’ve been climbing and that the shoes he lent me 15 years ago have come in for a fair bit of stick. As I hit send on the e-mail a thought suddenly occurs to me: Did Tim actually give me those shoes, or did he just lend them to me?

The e-mail comes back. He wondered where those shoes went. He duly goes up the wall. That makes two of us, then.