Q I recently experienced something weird and a bit mortifying. At a dinner party, I told what I thought was a brilliant anecdote about a bizarre encounter on a train. Everyone laughed … until my friend pointed out that she was the one who’d told me that story, weeks earlier. I had no memory of her telling it. I genuinely thought it had happened to me.
This isn’t the first time. I’ve caught myself repeating jokes or “remembering” a dream that turns out to be from a book I read. I feel like a fraud! Or like I’m slowly losing my mind. I’m not intentionally copying anyone. In fact, I’m hypersensitive to plagiarism. But moments like this shake my confidence. Is this just poor memory, or is something deeper going on? I’m in my late thirties, in good mental health and otherwise sharp.
I’m not worried about dementia, but I do feel confused about what’s happening in my brain. It’s so embarrassing. Is this a me-problem or do our minds sometimes steal from others without our knowing?
Sam
A What you are describing is a fascinating glimpse into how human memory works — messy, fluid, fallible, and often unintentionally creative.
You’re experiencing a psychological phenomenon known as cryptomnesia — literally, hidden memory in Greek (“crypto” means hidden and “mnesia” means memory). It’s not lying or stealing, it’s more like your mind pulling something out of the archive with the label peeled off.
To reassure you, you are in good company. Mark Twain once received a letter accusing him of plagiarising part of a speech, only to realise, to his horror, that the exact passage had been written years earlier by a friend.
Helen Keller, in childhood, was accused of copying a story she thought she had invented, which devastated her and created a lifelong anxiety about authorship. And George Harrison’s song My Sweet Lord bore such a strong resemblance to He’s So Fine by the Chiffons that it resulted in a court case, where the judge concluded that the copying was “subconscious”. As Salvador Dalí once said: “Those who do not want to imitate anything, produce nothing”.
You feel ashamed not because you’re dishonest, but because it threatens a sense of self and leads you to question where your ideas end and others’ begin. But these are existential questions not memoryrelated ones, and to understand cryptomnesia we need to understand how memory works.
We are constantly absorbing stories, ideas, snippets of conversation, turns of phrase, and storing them away without knowing it. This is implicit memory — content we’ve encoded without conscious intention. When that content is later retrieved (for example, in the middle of a lively dinner conversation), it doesn’t always come with its proper attribution tag.
Also, if it fits our personality or emotional experience, it may feel like ours. And this is where things get messy, because when implicit memory resurfaces, it doesn’t always announce itself as borrowed.
We like to think that memory is a tidy storage system and a fixed record of the past, where information is clearly filed by source and date. But psychologically and neurologically memory is reconstructive. So every time we recall something, we don’t simply retrieve it like a saved document, we rebuild it using context, fragments, emotion, and guesswork. Memory, therefore, is also derivative.
This is what Twain went on to describe, well before we could understand memory in the way that we now can. He did acknowledge incorporating ideas and phrases from other writers into his own work without realising it, and described this as “unconscious plagiarism”. He correctly concluded that to some extent, all writing is derivative, and therefore that conscious plagiarism is rare.
Memory comprises three core processes: encoding, storage and retrieval. Think of memory like a library. Encoding is the moment a new book is written and added to the catalogue — it’s how new information enters the system. Storage is how that book is shelved and maintained over time; sometimes it’s filed neatly, but other times it’s misplaced, damaged, or slowly forgotten. Retrieval is what happens when you go looking for that book. Occasionally it’s easy to find, other times it takes effort, and sometimes you pull out the wrong one or never locate it.
There are also different types of memory. Episodic memory stores what we remember, such as our first kiss. Semantic memory holds what we know, for example that whales are mammals. Procedural memory deals with skills such as riding a bike. And then there’s working memory, which is the mental Post-it note we use to juggle things in the moment, like remembering a phone number long enough to dial it.
All of these forms of memory rely on different regions of the brain: the hippocampus is crucial for forming new memories, while the prefrontal cortex helps with retrieval and decision-making.
Because memories are not stored in one neat corner and are distributed across complex neural networks, they are vulnerable to all kinds of glitches. This can result in, for example, an accurate memory of content but no memory, or an inaccurate one, of authorship.
Also, because memory is reconstructive, it’s susceptible to errors. We misremember timelines, merge events, or recall things that never actually happened. Sometimes we remember the gist but change the details. This is called gist-based memory distortion, a phenomenon where we recall the overall meaning (gist) but misremember or alter specific details.
Other times, we remember the details but forget the source: cryptomnesia.
"It leads you to question where your ideas end and others’ begin
All this is more likely to happen when we are tired or cognitively overloaded, or if the memory was encoded casually (during a conversation rather than deliberate learning), and also when the story or idea felt relatable or resonated emotionally. This all suggests that cryptomnesia happens to thoughtful, emotionally attuned, verbally fluent people more than most.
If you start being anxious and selfconscious about the possibility of cryptomnesia, this can make it more likely to happen. When we are overly focused on not copying others, our brain becomes overloaded. This constant self-monitoring adds cognitive strain, which reduces working memory capacity, making it harder to accurately track where an idea came from in the first place.
Anxiety also disrupts what’s known as source monitoring, which is the brain’s ability to tag memories with their origin — whether you read something, heard it in conversation or thought it yourself. Worry and selfdoubt can blur these mental labels, meaning we may recall someone else’s words as our own without realising it.
Finally, when we’re anxious, we become hyper-attuned to content that feels personally relevant. The more emotionally connected we feel to something, the more likely we are to absorb and internalise it. Later, when it resurfaces, it feels like ours because it fits.
In this way, anxiety doesn’t just cloud memory, it shapes it. So the more you fear cryptomnesia, the more susceptible you may become to it, not because you’re careless, but because that fear interferes with how memory actually works. What this means is that cryptomnesia isn’t a character flaw, it’s a quirk of being human.
We are, cognitively speaking, communal creatures, so our stories will bleed into each other’s. What can you do? Well, you can’t eliminate cryptomnesia entirely, but you could build awareness and humility around your storytelling. You could, for example, preface anecdotes with: “I think this happened to me…” or “I may have heard this somewhere, but…”. Also, accept correction without shame — others are more likely to laugh and relate than judge.
Cryptomnesia can be seen as a metaphor for how we unconsciously remix memory and meaning, retelling borrowed stories not to deceive, but to make sense of something in ourselves that hasn’t yet found its own voice. So, don’t be embarrassed or feel guilty for being human. Next time it happens, smile, apologise. And tell your friend that they clearly have excellent material. I wish you well.
If you would like Professor Tanya Byron’s help, email proftanyabyron@ thetimes.co.uk
