Sure, but surely that’s how it feels from the inside when your mind uses a LRU storage system that progressively discards detail. I’m more interested in how much I can access—and um, there’s no way I can access 2.5 petabytes of data.
I think you just have a hard time imagining how much 2.5 petabyte is. If I literally stored in memory a high-resolution poorly compressed JPEG image (1MB) every second for the rest of my life, I would still not reach that storage limit. 2.5 petabyte would allow the brain to remember everything it has ever perceived, with very minimal compression, in full video, easily. We know that the actual memories we retrieve are heavily compressed. If we had 2.5 petabytes of storage, there’d be no reason for the brain to bother!
If we had 2.5 petabytes of storage, there’d be no reason for the brain to bother!
I recall reading an anecdote (though don’t remember the source, ironically enough) from someone who said they had an exceptional memory, saying that such a perfect memory gets nightmarish. Everything they saw constantly reminded them of some other thing associated with it. And when they recalled a memory, they didn’t just recall the memory, but they also recalled each time in their life when they had recalled that memory, and also every time they had recalled recalling those memories, and so on.
I also have a friend whose memory isn’t quite that good, but she says that unpleasant events have an extra impact on her because the memory of them never fades or weakens. She can recall embarrassments and humiliations from decades back with an equal force and vividity as if they happened yesterday.
Those kinds of anecdotes suggest to me that the issue is not that the brain would in principle have insufficient capacity for storing everything, but that recalling everything would create too much interference and that the median human is more functional if most things are forgotten.
EDIT: Here is one case study reporting this kind of a thing:
We know of no other reported case of someone who recalls
personal memories over and over again, who is both the
warden and the prisoner of her memories, as AJ reports. We
took seriously what she told us about her memory. She is
dominated by her constant, uncontrollable remembering,
finds her remembering both soothing and burdensome, thinks
about the past “all the time,” lives as if she has in her mind “a
running movie that never stops” [...]
One way to conceptualize this phenomenon is to see AJ as
someone who spends a great deal of time remembering her
past and who cannot help but be stimulated by retrieval cues.
Normally people do not dwell on their past but they are oriented to the present, the here and now. Yet AJ is bound by
recollections of her past. As we have described, recollection
of one event from her past links to another and another, with
one memory cueing the retrieval of another in a seemingly
“unstoppable” manner. [...]
Like us all, AJ has a rich storehouse of memories latent,
awaiting the right cues to invigorate them. The memories are
there, seemingly dormant, until the right cue brings them to
life. But unlike AJ, most of us would not be able to retrieve
what we were doing five years ago from this date. Given a
date, AJ somehow goes to the day, then what she was doing,
then what she was doing next, and left to her own style of
recalling, what she was doing next. Give her an opportunity
to recall one event and there is a spreading activation of recollection from one island of memory to the next. Her retrieval
mode is open, and her recollections are vast and specific.
Sure, but surely that’s how it feels from the inside when your mind uses a LRU storage system that progressively discards detail. I’m more interested in how much I can access—and um, there’s no way I can access 2.5 petabytes of data.
I think you just have a hard time imagining how much 2.5 petabyte is. If I literally stored in memory a high-resolution poorly compressed JPEG image (1MB) every second for the rest of my life, I would still not reach that storage limit. 2.5 petabyte would allow the brain to remember everything it has ever perceived, with very minimal compression, in full video, easily. We know that the actual memories we retrieve are heavily compressed. If we had 2.5 petabytes of storage, there’d be no reason for the brain to bother!
I recall reading an anecdote (though don’t remember the source, ironically enough) from someone who said they had an exceptional memory, saying that such a perfect memory gets nightmarish. Everything they saw constantly reminded them of some other thing associated with it. And when they recalled a memory, they didn’t just recall the memory, but they also recalled each time in their life when they had recalled that memory, and also every time they had recalled recalling those memories, and so on.
I also have a friend whose memory isn’t quite that good, but she says that unpleasant events have an extra impact on her because the memory of them never fades or weakens. She can recall embarrassments and humiliations from decades back with an equal force and vividity as if they happened yesterday.
Those kinds of anecdotes suggest to me that the issue is not that the brain would in principle have insufficient capacity for storing everything, but that recalling everything would create too much interference and that the median human is more functional if most things are forgotten.
EDIT: Here is one case study reporting this kind of a thing:
Perhaps you are thinking of this (i think) autobiographical essay by Tim Rogers? He also talks about it in his 5th chapter of his boku no natsuyasumi review.