In 1970, George Harrison released "My Sweet Lord," a luminous, devotional song that went on to top charts around the world. Six years later, a US federal judge ruled that the melody was strikingly close to "He's So Fine," a 1963 hit by the Chiffons. Harrison was found to have infringed the copyright. The judge did not think Harrison had lied or schemed. He concluded the copying was subconscious. Harrison had heard the earlier song, forgotten hearing it, and then felt the tune arrive as his own.
That's the unsettling part. From the inside, a stolen idea and an original one feel exactly the same.
The feeling of having a new idea is not evidence
Psychologists call this cryptomnesia, from the Greek for "hidden memory." It happens when a memory resurfaces without the label that says where it came from. The content comes back. The origin doesn't. So your mind, which is always quietly trying to make sense of things, files the idea under the most flattering explanation available: I thought of this.
This isn't a character flaw. It follows from how memory is built. Researchers describe a process called source monitoring, which is how we work out whether a memory came from experience, from a conversation, from something we read, or from our own imagination. Marcia Johnson and colleagues developed this framework, and a central finding is that source information is stored more weakly than content. Facts and phrases survive. The "who told me this, and when?" tag fades first.
In a well-known set of experiments from the late 1980s, Alan Brown and Dana Murphy had people take turns generating examples from categories, like types of sports or birds, in a group. Later, the participants were asked to come up with new examples on their own. A real portion of the time, people offered answers that had already been given, including their own earlier ones, and presented them as fresh. They weren't cheating. They believed they were being creative.
Why it hits thoughtful people hardest
Cryptomnesia is not a risk reserved for songwriters. It's most likely when you:
- Take in a lot of information. Heavy readers, podcast listeners and people with busy group chats have more sources to lose track of.
- Let time pass. The longer the gap between hearing something and using it, the more the source tag decays while the idea itself stays.
- Think alone, with no one to check you. If nobody else is in the room, nothing interrupts the feeling of originality.
- Are distracted when you first encounter the idea. Attention at encoding matters. A half-heard remark during a meeting can come back later as your own insight.
There's also a quieter version that has nothing to do with other people. You can forget your own earlier thinking. You have a breakthrough about your career in March, forget it, and rediscover it in September with a rush of excitement. The same machinery is at work. It's why many people recycle the same "new" resolutions for years without noticing the pattern.
What it costs you
The obvious cost is professional. You pitch a framework in a meeting, and a colleague later says, gently, that it sounds a lot like something they mentioned in the spring. Or you write an essay and realize that one of your best sentences is lifted from a book you read two years ago. Both feel awful, and both are avoidable.
The less obvious cost is to your own relationships and your sense of self. Ideas passed between friends, partners and mentors carry a kind of social currency. When someone shares a thought and later hears it come back from you without acknowledgment, even by accident, it can sting in a way neither of you can quite name. And if you can't trace your convictions to where they came from, you can't evaluate them. A belief you absorbed from one confident podcast host feels identical to a belief you reasoned your way into.
Knowing the origin of an idea is part of knowing whether to trust it.
The fix is boring and it works
You can't will yourself into better source memory. Trying harder to "remember where I got that" mostly doesn't work, because the information has already faded. What does work is externalizing the source at the moment of capture, while it's still in your head.
The principle is simple: an idea should never be written down alone. It should travel with a small tag saying where it came from and when.
This takes a few seconds, which is exactly why it survives. Any version that requires formatting a citation will die within a week. The tag only needs to answer three questions: Who or what? When? Mine, theirs, or a mix?
The third question is the most useful. Many ideas are genuinely hybrids, where someone said something and you pushed it somewhere new. Recording that honestly ("Dana's point about handoffs, my extension: apply it to onboarding") preserves both the credit and your real contribution.
Your next moves
- Add a source line to your next ten notes. Write the idea, then add one short line beneath it: where it came from (a person, a book, a talk, "shower thought") and today's date. Ten repetitions is enough to make it automatic.
- Use three labels: Heard, Read, Mine. If you hesitate over a note, that hesitation is worth recording. Mark it "unsure" rather than defaulting to "mine."
- Before presenting an idea, run a thirty-second search of your own notes. Search a few distinctive words from your pitch, essay or toast. If an old note turns up, you've either caught a source or discovered you're repeating yourself. Either result is useful.
- Credit out loud, early. When you build on someone's remark, say so in the moment: "This came out of something Sam said." It costs nothing, and it trains you to keep tracking origins.
- Do a quarterly sweep. Skim your last three months of notes for ideas that appear more than once. Repeats often mean a real theme, or a lesson you keep re-learning.
Originality is mostly honest bookkeeping
There's a comforting side to all this. Almost nothing anyone creates is built from nothing. Harrison's tune came out of a lifetime of listening, and so does your best thinking. The goal isn't to purge every influence. It's to know your influences well enough to credit them, and to know your own contributions well enough to trust them.
The people who seem reliably original often aren't the ones with the most mysterious flashes of inspiration. They're the ones who keep decent records, so that when something feels new, they can check.
That's the quiet case for a notes app that opens instantly. If recording a source takes more than a couple of seconds, you won't do it at the moment it matters, which is when you hear the thing. Pagebox is built for that moment: it opens in under a second, and a daily journal page or a simple list is a place to drop the idea with its who and when attached. If you'd like to try it, you can find it at pagebox.lumenlabs.works. But the habit is the point, and a paper margin would do the job as well.