I have an inconvenient habit of writing myself cryptic messages. I don't intend them to be cryptic - it's just that when I come to read them later I have no idea what they mean.

I was flicking through my trusty Evelyn Rose Complete International Jewish Cookbook a while back when I came across a note, written in red pen and capitals, saying, "DO NOT EVER MAKE THIS AGAIN AS LONG AS YOU LIVE".

It was next to a completely innocuous-looking recipe for aubergine, tomato and cheese casserole.

I stared at the page, trying to recall anything whatsoever about the cooking experience that had led to me writing this. What on earth could have gone so badly wrong? I like aubergines, and tomatoes, and cheese. And I love Evelyn Rose. I love her recipes because they always work. She's a Jewish Delia Smith, giving us dependable, sensible classics that use ingredients you've heard of and techniques you can follow.

I'm an enthusiastic cook, and I do find it fun now and again to launch into a complex and esoteric recipe by the likes of Ottolenghi - scaling remote mountains in order to gather a rare herb from the ingredients list, then spending several days marinating, macerating, sautéing and reducing until I have the desired result.

But let's face it - I am a frazzled working mother with poor organisational skills. So, for the majority of the time, if I need a recipe or just some advice for a particular cooking technique, Evelyn is my go-to person.

It was therefore hard to understand how I had managed to become so traumatised by a light vegetarian supper dish.

In a similar vein, I recently came across an entry in my iPhone calendar for about three weeks hence, saying: "Don't park beneath that tree."

This caused no end of anxiety. Which tree? And why not? What if I were to inadvertently park beneath it without knowing it? The phrase "that tree" implied that, when I wrote myself the warning, the (possibly evil) nature of the tree was so obvious to me that no further explanation was required.

As the day in question approached, I considered parking my car entirely away from any tree. But that's not easy in London, where parking spaces are scarce enough as it is.

There was also the possibility that my tree-related fate was already pre-ordained, so trying to avoid parking beneath trees was going to do me no more good than if Sleeping Beauty had written in the calendar for the day of her sixteenth birthday: "Do not go near any spinning wheels".

In fact, the tree day passed without incident and I never did find out what I'd meant. But I still don't seem to learn.

The "Notes" app on my iPhone is a fruitful source of completely incomprehensible messages-to-self. I found, for example, this idea I'd jotted down for a column:

Old lettuce; endless introspection; people I've never heard of; quaint references to the Internet.

I have no idea whatsoever what was going on in my mind at the time. What topic could possibly bring together all of those themes?

A quick bit of canvassing on social media revealed that this is a very common phenomenon. Friends shared illegible shopping lists, surreal phrases, and random rows of letters and digits.

One person said she'd written "Tuesday" on a Tuesday slot in her calendar, which, while accurate, was not necessarily helpful.

Others had calendar entries saying simply, "Event" or "Lunch", which doesn't really narrow things down very much. And one person had written a single "!" on a forthcoming afternoon - and is now waiting to find out what worthy of exclamation is going to happen that day.

An unexpected side effect of this research is that friends started suggesting explanations for other people's cryptic notes - with amazing success.

This made me wonder whether I ought to start a website where people can crowd-source help in decoding their own messages. Thinking about the aubergine casserole, though, perhaps I need to improve my own communication systems first.

I do feel that it's important to listen to my past self even if I don't understand her. The cover of my Evelyn Rose finally fell off after 20 years, and I treated myself to a new copy.

Before throwing the old one away, I transferred all the hand-written notes I'd added to various recipes over the years: "Needs an extra 5 minutes in the oven … Don't bother with the cornflour … Quite tasty but not really worth the effort".

Then I fetched a red pen, and faithfully wrote next to the aubergine, tomato and cheese casserole: "DO NOT EVER MAKE THIS AGAIN AS LONG AS YOU LIVE."

@susanreuben