One day, years ago, I went to the cinema. I can’t remember anything about the film, what it was called, whether it was any good, but I do remember one thing about that day. As I was heading out of the screening, I found myself walking behind two guys. They were chatting. My mind must have screened out the more mundane content of their conversation, as nothing stood out. Until I heard the following words:

“And then I dreamt I hit my mother. With a lettuce leaf!”

I resisted the temptation to tap the speaker on the shoulder and admire his restraint. Frankly, I would want to lob the whole damn lettuce at mine. Probably an Iceberg. But I had to duck into the Ladies’ restroom and give way to hysterical laughter. There was no way on earth I could possibly keep a straight face for long after overhearing this comment. What had this poor woman done to deserve being brutalised by a lettuce leaf? Why did this anti-Oedipus have vegetable violence lurking in his subconscious? The images his words created were irresistible.

The Brits have pretty much perfected the art of Keeping A Straight Face. Under the greatest of provocation, we maintain an expressionless visage. When we witness pratfalls and encounter verbal faux pas, our facial muscles remain unflexed. Whether out of politeness, fear of causing offence, or not wishing to draw attention to ourselves, we endeavour to show not the slightest sign of physical or emotional reaction. It’s just not socially acceptable to laugh when someone falls over, even if it’s the funniest thing you’ve seen all day. So however much I wanted to laugh, I could not draw attention to myself and reveal that I had overheard this comment.

So to this day, the speaker has no idea that he was overheard. He probably forgot the lettuce leaf dream as soon as he mentioned it to his friend. The friend probably doesn’t remember it either. But that dream lives on in my memory. It wasn’t even my dream, yet every time I see a lettuce I think of an innocent woman being assaulted with salad. Who knows, maybe dreams with a horticultural theme run in the family. Perhaps she dreams of beating her son around the head with a cucumber or firing a volley of radishes in his direction. Be careful next time you’re in the greengrocer’s. It’s a dangerous place.