MY mother was a wise woman and I live much of my life according to her advice. For instance, I avoid running with scissors, to the extent that when I have gone out for one of my runs I have never taken scissors with me.

I always wear clean underwear in case I am in an accident. I always say “thank you” to bus drivers in case I need one of them to wait for me at the stop and they will remember me as that nice polite man. Obviously, this has never happened, but I have faith that one day it will.

And she told me never to geg in on other people’s conversations. “Geg in”. It’s a Liverpool expression my mum used, the meaning of which you can probably gather from context.

The point is, I usually keep my nose out, despite great temptation. But sometimes I cannot help myself. This is a very rare occurrence, and only takes place when the people involved in the conversation are saying something so stupid or objectionable that the only responsible course of action is to geg in, and geg in hard.

And it has happened to me twice this week. The first time was on a train. It was late and I was tired, so my resistance was down. Across the aisle from me were three men in their mid-30s to early-40s who were explaining Star Wars to each other in tones which suggested a) deep and long-lived familiarity with the subject; and b) deep and recent familiarity with scrumpy.

However, they could only demonstrate the latter. They were loud and they were sure of themselves and they were wrong. They announced to the carriage that the first Star Wars film was always Episode 4, that The Last Jedi was the worst Star Wars film ever, and that Revenge Of The Sith was the second best Star Wars film.

These are all completely untrue. I am only a vague Star Wars fan, and even I knew they were talking absolute nonsense. I put my anti-drivel earphones in, but I could not turn up the volume high enough to drown out the levels of rubbish they were spewing. My levels of rage were building…

Eventually one got off and the other two continued talking in lower tones. They moved away from the subject of Star Wars and on to “this TV series with the man from Miranda, who plays the Devil, who gets fed up being the king of Hell, so he moves to LA and becomes a detective.”

“Ooh, that sounds interesting,” said the other man. “What’s it called?”

“Oh, I’m trying to think,” said the other man. “Erm… Erm…”

This is none of my business, I thought. Stay out of it. He’ll get it…

“Erm… Erm… Oh, I know. Luther!” he said.

I yanked out my earphones with a pop. “LUCIFER!” I shouted.

They were shaken. The whole carriage was shaken, I expect, by the sound of a man crying out the name of the Devil. “Yeah, all right, mate,” said the Luther-idiot. “Calm down.” I flushed, shoved my earphones in, and stared at the floor for the rest of the journey. Mum was right. I would never do this again…

Two days later, I had finished a long shift making a newspaper and was on my way home. It was 10.30 and I needed milk, so I called in at a small branch of a large retailer.

There were three checkout staff chatting among themselves, so I decided not to bother them and used the self-checkout. It took a while because of improvements to the system which make things slower, and I tuned into their conversation.

They were talking about newspapers and journalism in general. And then one of them, a young man, said: “Yeah, well, all journalists are…” and then a word you wouldn’t hear on Cbeebies.

I forgot my promise, and marched over to him. “Two things, pal,” I said. “First, swearing in front of customers is unprofessional. And second, if you’re going to slag off journalists, try not to do it in front of somebody who’s just slogged his guts out for nine hours making a newspaper.”

I had stood up for my profession, my friends, and myself. My heart was racing, my blood pumping. I felt empowered, readers.

Then I turned on my heel and strode away with purpose. Straight into a stack of shopping baskets.

Mum was right. Never geg in.