When I was at primary school, I had a teacher who either hated children, was on a huge power trip, or probably both. During lunch, she would force the entire school to sit and eat in total silence. Anyone who made a sound, she declared, would have to write an essay about the inside of a ping-pong ball.

She chose this particular essay topic as a punishment because it’s so difficult to find anything to say about the interior of a white, featureless sphere. I remember thinking, though, that I’d quite like to give it a go. It seemed like it could be an interesting challenge.

There was never any chance of me actually having to do so — I was far too scared of the teacher to utter a word during lunch. But I’ve thought since about the general concept of having to write on a topic of someone else’s choosing. So this week, I asked my Facebook friends each to put forward a single word as a subject for a column, out of which I would select one.

Most of the words submitted represented abstract ideas rather than physical objects, with “consequences”, “hypocrisy” and “serendipity” all appearing twice.

Two writer friends suggested themes that, amazingly, matched their own upcoming assignments — along with a word count that also coincided.

One proposal was, “pickles: cucumber and metaphorical”.

Some friends were just trying to make life difficult for me, with words that I had to look up. For example, “thermoclines” (an abrupt temperature gradient in a body of water) and “fulcrum” (the point against which a lever is placed to get a purchase). Thanks to those people.

In the end, I decided to opt for “fruit”— and specifically, bananas. Draw whatever conclusion about the depth and complexity of my mind that you wish to, from this decision.

As bananas are not indigenous to the Middle East, there is no mention of them in the Torah. I feel this is probably fortunate. If, for example, the spies sent forth into Canaan had brought back, “a branch with a single cluster of grapes… and some pomegranates and figs and a bunch of bananas,” (Num 13:23) then the Promised Land would have sounded less like the holy destination of the Children of Israel and more like your local supermarket.

Speaking of which, some time ago I tried to order six bananas as part of my weekly Tesco shop, but I accidentally ordered six bags of them instead. (It’s easy to do when you’re shopping online). I decided that the most pragmatic move would be to offer the surplus to the neighbours.

“Can I be the one to take them round?” asked my son, Isaac, who was eight at the time.

“Sure, so long as you only go to houses we know,” I replied. I assumed he would simply put them in a bag, knock on a few doors and say, “We’ve bought too many bananas. Would you like some?”

Having already lived with him for eight years, I should have known better.

He disappeared upstairs, re-emerging some time later with a homemade usherette tray to carry the fruit, along with a banner saying “Free bananas!”. Before setting off, he shared with us the banana-related song he had made up to sing at each door.

Shortly after he returned (mission successful) I received a text from our next-door neighbour whose house was on the market. “Thank you for the bananas,” the message read. “However, we had people viewing the property when Isaac came round.” The implication was that having a small person turn up at the door singing songs about bananas had compromised the sales potential of their home. They might have been right.

There’s so much more I could say about bananas… the fact that we own several items of specialist banana equipment, including a banana bag (for preserving them in the fridge), a banana guard (for stopping them getting squashed when you’re out and about) and a banana susan (a hook for hanging them on).

And my father’s tendency to talk about them whenever we’re eating dessert, whether or not they’re on the menu. (Inevitably there will come a point towards the end of a meal where I have to say to him, “Dad, you’re talking about bananas again”.)

Part way through writing this column, I noticed that the little picture on the screen next to my computer ID was no longer of me, but of a banana. I was considerably disconcerted by the idea that Apple had started tracking my activity and changing my picture accordingly.

Then I discovered that my phone no longer thought I was called “Susan” but rather, “Big Banana Face”. And I remembered that I had told Isaac (now 12 and highly tech savvy) what I was writing about this week. Once again, I should have known better.

@susanreuben