The Seven-Year Rule
69 comments
·April 26, 2025SirHumphrey
cwbrandsma
That sucks, since I developed a neurological issue from Covid I could really use a refresh of my nervous system.
LPisGood
I once heard that this is an oft repeated myth, that neurons are not replaced throughout life.
It seems to me to that what you said is true, but for some odd reason I have a recollection of reading a debunking of this. Does anyone know what I might be thinking of?
chewbacha
They are just very very slow. It does happen but the turnover is not fast and certainly not every 7 years.
joshuaturner
ah man I really wanted to be a new person
scoofy
It doesn’t matter whether the cells actually change. The persistence of the self, and even consciousness itself, are very possibly an illusion.
jstanley
Consciousness is the only thing that can not possibly be an illusion.
Whenever this comes up I have to wonder if half the people are secretly p-zombies and actually genuinely aren't sure whether consciousness is an illusion because they've never experienced it? I know that's not a very charitable take but I just can't see how any conscious being could imagine that consciousness could be an illusion!
Consciousness isn't the illusion, consciousness is the audience!
satisfice
Consciousness is a phenomenon, but not an illusion. An illusion is something that seems to be there, yet is not. But consciousness is a self-evident experience.
However, there are gradiations of consciousness. The experience we have on the edge of sleep is qualitatively different than the experience even five seconds after waking up to a cat attack in the middle of the night (I have experienced that).
malux85
Then just believe it,
Abstract thing A you can never measure gives you joy and renewal
Abstract thing B you can never measure holds you back and limits you
The practical difference is zero or near zero, so go and be joyful and happy!
daxfohl
A body's atoms do completely recycle every 5-7 years though. 98 percent are recycled annually. Weird.
darkr
Incorrect
g0db1t
[dead]
efitz
“My cells” are not “me”.
Without resorting to metaphysics, “I” am a slowly-but-constantly changing set of experiences, memories, predilections and preferences that happens to be instantiated in and associated with a particular physical body. My relationships with other people tend to be the most important things to me and the things that most shape whatever direction my identity is going.
My body is not the same exact set of cells or molecules that I was 30 years ago. But I’m like the Ship of Theseus- the essence of what I am is a direct consequence of my formative experiences regardless of what pieces I’m built of at any given moment.
It’s my choice (within the constraints of how brains work) of how much I let past experiences affect my current behavior. But I can’t forget those experiences and if I could, then I would not be the same “me” in a much deeper sense than just having different cells or molecules.
johnfn
> I recently spoke with a friend who was still dwelling on something that happened thirty years ago. “Why do you care?” I asked him. “That was four versions of you ago. That person doesn’t exist anymore. Move on.”
Do you think this actually helped your friend? In any way?
travisd
Of course! It helped your friend realize what kind of person you are and hopefully spurred them to find better friends who possess actual human empathy.
gmuslera
So if Theseus was aboard his ship for many years it would add another layer of it that ship still is his own?
In Vernon Vinge’s A Fire Upon The Deep you have pack of dogs that are not so smart individually, but they had a pack personality that was smart. Even (for one case in the book) the dogs could be replaced but the personality remained.
Changing individual cells doesn’t change what is the you of your consciousness and memories. Of course, even without cell replacement you change with time, new memories, insights and so on, but both changes happen at different abstraction levels.
globnomulous
Peter F. Hamilton's Pandora's Star contains a wonderful variant of this thought experiment: in the future he describes, memories are editable; so it's possible to commit a crime, like murder, and then wipe all memory of it, so that you are, from your own perspective, innocent. The justice system, of course, says otherwise. The metaphysics (whether or not it's possible to step into the same river twice) don't matter. Technological advancement dictates the answer to the philosophical question about continuity of the self and guilt.
borski
> Changing individual cells doesn’t change what is the you of your consciousness and memories.
It’s a metaphor.
HellDunkel
It feels so strange to read blogposts like this in 2025. The level of mediocrity makes you question if this has been created by a human or an ai bot. Next you start questioning yourself why you still look into your smartphone like a junkie.
mattlondon
Regret is real for a reason.
"Those who ignore history are doomed to repeat it" as they say, even it was over 7 years ago...
metabagel
How much time and energy should you spend today regretting your mistakes of 10 or 20 years ago?
tsimionescu
Depends a lot on the mistake and your life since then. Is it something you could still fix today? Is it a mistake you keep repeating? Is it a huge mistake that still directly impacts your relationships and today in some way?
ludicrousdispla
I think mistake is an overused word, and a choice that qualifies as a mistake in the future may not be judged as a mistake now.
Simply put... we make choices based on the information we have now. And our future judgment of our choices should account for the information we had back then, most of which has probably been forgotten.
But to answer your question, we shouldn't regret our mistakes but it is very good to remember them.
dgfitz
I think the correct answer in terms of mental health is: as little time as possible.
The actual answer is more complicated. Someone who got locked up for 25 years knowingly committing a significant crime might regret it for the majority of their sentence, at least.
tsimionescu
I don't think this is true at all. Living your life ignoring all of your past mistakes can be just as unhealthy as dwelling on them needlessly. Dwelling on past mistakes can lead to hopelessness and depression, but ignoring them entirely can lead to narcissism and repeating damaging patterns.
blaze33
Seems to me the Dalai Lama used the 7 years cell replacement thing as a metaphor to explain some classic Buddhist teachings.
> still dwelling on something that happened thirty years ago.
Exactly that: clinging causes suffering.
Buddhism also goes a step farther, they have a whole doctrine about emptiness and no-self: there's no permanent or unchanging self to be found.
JasonBorne
The paradox to this is we want to stay connected to some things that are important to us such as family and deny the things that cause us pain.
akubera
I'm reminded of the SMBC comic https://www.smbc-comics.com/?id=2722 which resonated with me. If it takes ~7 years to master something, you should dedicate yourself to becoming good at it. Or at least you don't have to tie your identity to what you do you right now; you can reinvent yourself and experience more from of life, but you have to give yourself the time to do so.
It's been almost 14 years since that was published, so maybe some self-reflection is due.
sentimentscan
That explains this: https://en.wikipedia.org/wiki/The_Seven_Year_Itch idiom/movie with Marilyn Monroe
didgetmaster
Is that why the IRS insists that we keep the past 7 years of our tax records?
FrankWilhoit
The whole point of learning is that it is cumulative.
metabagel
It can be emotionally freeing to learn from the mistakes of that other person you used to be, rather than your own mistakes which you return to again and again with feelings of regret.
metabagel
So basically, it’s a neat mental trick to provide emotional distance and allow you to move on with your life, and also allow you to keep your mental model of yourself fluid (changeable).
FrankWilhoit
Key word: trick.
>>> The person you are today doesn’t share a single cell with the version of you from seven years ago. (This is, of course, a generalization as some cells regenerate much faster and others a little slower.)
No, that is not even remotely true. Most of the neurons in the central nervous system (the part of the body one could argue does the most of thinking) stay mostly the same from adulthood to death[1].
[1]: https://en.wikipedia.org/wiki/Neurogenesis