Lucy Baring has wheel envy.

I feel as if I’ve acquired an obedient pet. Every so often, I glance behind me to check if it is, indeed, doing as it’s told because I can sense a whiff of disgruntlement aimed in my direction. However, I don’t want to appear a novice because that would make me look even more foolish than I inwardly feel.

Why on earth, I ask myself, as I disentangle us from a neighbouring pushchair, have I never had a suitcase on wheels before? Two reasons. First, I’m married to a man who thinks wheels are for wimps. Second, having once lugged the contents of my wardrobe across the globe, never to be worn, I’m a light traveller. Too light. I usually freeze and have to cadge shampoo off fellow guests.

When I arrived at Heathrow, I had a holdall over my shoulder. It was small, but very heavy as it was filled with sketchpads and tubes of paint. I was going on a painting course, which is a source of confusion to the family and myself as painting is not one of my hobbies. I failed my art O level.

But there I was, with a bag that was weighing me down and I felt extremely hot. In an unnecessary panic, I’d thrown away my toothpaste before going through security and so was aiming for the chemist when my eye was drawn by the luggage shop next door. I had no intention of buying a suitcase, but I had plenty of time — I wasn’t governed by the seat-of-your-pants travel habits of my husband.

I was approached by a sales assistant, who opened cases to show me a myriad of zippy compartments over which I obligingly cooed. The other assistant was fully engaged with a man who was looking at the superior side of the store. I suspected that he was also killing time (as he was already in possession of a nifty bag on wheels), so, when he said he must just check the departure time of his flight and disappeared from the store, I thought to myself ‘Ha, he’s never coming back’.

I asked my assistant if the contents of my heavy holdall would fit into the neat black cube he was currently opening for me and, although he was terribly disappointed that I might consider one without the padded laptop compartment, he said that it would. Before I had time to consider this gross act of disloyalty to Zam, I was handing over my card and acquiring my new pet.

I was told that I could decant one bag into the other right there on the table in the middle of the shop and, although I didn’t really want to display my T-shirts and underwear to Terminal 5, I remembered that the ladies loo was about a mile away and, anyway, the other customer had just reappeared and I wanted to see how that panned out.

He had 20 minutes until his flight, he said, slightly out of breath, and would like to purchase both suitcases right then and could the assistant help him repack and here was his card. When she hurriedly gave him the total (which was a four-figure sum), he nodded without stopping and the race was on.

I felt my heart rate soar, because he’d only got 20 minutes and what was he thinking of, buying such expensive suitcases and repacking and how far away was his gate? I took a deep breath and reminded myself that I must not take on the stressful travel-management or spending habits of total strangers.

I took my new pet for a walk. In fact, I went as far as the ladies loo because, well, I was now light and free and not hot. I negotiated the ramp down to the airplane, although that wasn’t entirely straightforward, and I heaved the case up into the overhead locker (those wheels are damned heavy).

And now, as I disembark, I try to look nonchalant about my new pet instead of ridiculously pleased, but that’s when I realise that other people’s pets do not, in fact, have two wheels, like mine. They all seem to have four.