I HAVE been spending a lot of time on trains lately, like Michael Portillo without the inexplicable television career.

Nevertheless, train travel still feels quite glamorous to me, in a way that bus travel no longer does. I do not know why. Maybe if they installed £1.50 Mars bar shops and complicated toilets on buses I would feel differently.

In any case, I was resting my head against the window, counting the trampolines in people’s back gardens, as the train sliced through the country. I wondered who it was who first came up with the idea of putting a net around trampolines, and exactly how big his mansion made of pure gold and unicorn hair must be, when I saw him.

This was not the inventor of trampoline nets – probably – but the man who would ruin my journey. He appeared in my window as the descending darkness turned it into a mirror, and it was hate at first sight.

I couldn’t decide at first what I hated about him most. Was it his youth? Was it was the way he flopped into his seat and used the seat opposite as a sort of pouffe? Was it the gigantic headphones he was wearing over his flat cap, attached ludicrously to a tiny iPod?

No to all of those. It was the way he wore a white T-shirt and scarf. I cannot tell you exactly why it set the alarm of my loathing for two minutes after I woke up, but it did.

It was stupidity, probably. The man had either left the house without a coat on one of the coldest days of the year, but remembered a scarf, or he did not see the correlation between being cold and wearing only a T-shirt.

I will refer to the man hereafter as Scarface – “scarf” because of his scarf and “ace” because of sarcasm. Scarface sat, nodding his head gently to the rhythm of the song I could barely hear because of his enormophones. I turned away from him, but had no respite because of the reflection in the window.

And so I stared at the back of the seat in front of me, becoming increasingly annoyed by the fact I had received a now ineligible HMV voucher for my birthday the day before the firm went into administration.

I likened it to handing over money to a shop assistant who goes behind the counter to pick up your goods, who is then distracted in her search by the news that her company is going bust, and then comes back to the counter to say that she won’t give you the item for which you’ve just paid. And no, you can’t have your money back. It would be the most disappointing trip to Argos ever.

“Oi, mate,” came a voice, in the unmistakable tones of a middle class boy condescending to trade. I turned towards Scarface.

“I’m going the toilet. Can you watch my bag?”

Before I could say anything, he was off, leaving his canvas iPad-and-bottle-of-water bag, on the seat. I sat staring at it, grimly hating myself for doing what he asked.

For the second time in two weeks, somebody going to the toilet on a train was messing up my journey.

I started to think about him. I bet he was the sort who said “Can I get…?” instead of “May I have…?” I bet he was the sort who didn’t go to HMV and didn’t understand that unless money is handed over by somebody at some stage, there will be no content for him to download illegally. I bet it was his fault that I had an HMV card worth less than the plastic from which it was made. His and his stupid scarf’s.

And I wondered what he imagined I would do if somebody did try to take it.

Was he expecting me to leap into action if Raffles came along in his stripy jumper and domino mask? Would I die to save his tablet and ready access to Facebook?

No, I would not. I got my paper out and started reading, ignoring the bag until he came back. It served him right for being stupid.

I do not want you to think I am prejudiced against stupid people. I count several stupid people among my friends. I just think they should practise their stupidity behind closed doors, in the privacy of their own homes, and not be shoving it in my face when I am just trying to get through the day.

Portillo wouldn’t put up with it, and neither will I.