What would it be like to live forever? Would you run out of new things to do, new things to learn, after a few thousand years? Let’s see if we can imagine it. Here’s the setup: suppose, for the sake of argument, that we have been granted eternal life. We have some kind of “spiritualized” bodies that will never get sick or wear out, and our minds will remain sharp. What about our memories?
There are two possibilities: either we will be able to remember everything perfectly, or not. First, let’s suppose we will have perfect memory. I used to think that that would be a wonderful thing, never needing to search for the right word, never forgetting the details of that pleasant afternoon, but I didn’t really consider the implications. Think about it. Perfect memory would mean remembering everything—every bit of minutia—how many breaths we took and what each one felt like, everything we saw, every sound we heard, every thought we processed in each moment. This presents a problem. If I remember every single detail of an event that took place last week—every detail, as if I were experiencing it now—how would I know this was something from the past, and not something I am experiencing now? How could I tell the difference between then and now? How would I know that event had ended, if I could still remember every detail perfectly as if it were still proceeding? After all, how do we know that what we are experiencing is the present moment, and not just a remembrance of something? Memories are quite different from current experience. Even a vivid memory only grabs our full attention for a moment, after which we snap back to reality. If the past didn’t have a different character than the present, could we tell the difference?
But let’s slide past this problem. Let’s suppose there is a fix for it. Perhaps our memories will be “flagged” somehow, maybe they will have a sepia tone that distinguishes them from current experience, and we will be able to process this information automatically. That’s fine, then, but there is another problem with perfect memory. The memories keep accumulating. This would be a problem even with an ordinary lifespan. A lot of things occur in one’s life, and if we remembered every one of them, we would need better mental filing systems. Of course we would be prioritizing. The least important memories would be further down, and the more important to us near the top, easily accessible, but if we each have millions of memories, one per cent of which we consider important, that’s tens of thousands of items that we want access to. I assume that means we will have to have constantly increasing mental processing power. If we keep learning, keep having new experiences, in thousands, millions, trillions of years we are going to need so much intelligence just to maintain access to our memories, much less make good use of them, that we will hardly be recognizable as the persons we once were.
Alternatively, it may be that our mental power doesn’t increase, or not much. Instead, we would just have access to less and less of our memories over time. After a hundred years, we might each remember a million events, but only have practical access to a couple of thousand of them. Then after a hundred million years, we would presumably remember a billion events, but still have access to thinking about only the couple of thousand most important ones. The rest would be buried deep in our minds, in other words, the same as forgotten.
So we have come to the other possibility, that eternity would not involve perfect memory. In that case, what would we remember? As we are inundated in new experiences, we would eventually reach a practical limit to what our minds could hold and efficiently work with. Would we then stop learning anything new? Would we have no short-term memory left, and live only in the past? Or would we start dropping old memories to make room for the new? After trillions of years, that’s either a lot of living without new memories or a lot of old memories lost. How many memories could I lose and still be me?
When I read something I wrote fifty years ago, I can still recognize the writer. He’s not exactly me, but I recognize him as a younger, more naive version of me. I wouldn’t do now some of the things I did then, but I can still understand why I acted that way. After a trillion years, would “future I” still recognize the man I am now? After another million trillion years? Would that be me at all? If not, then why call it eternal life?
Eternal life comes down to three alternatives, then. Either (1) we would all keep increasing in intelligence as we keep learning, becoming more and more god-like in our mental ability, or (2) we would stop learning at all at some point, after which we would be essentially mindless automatons, or (3) we would keep learning new things and forgetting the old, losing most of what constituted our old selves. In none of these cases would we maintain our original identity. At some point, far in the future, we will have encountered so many astoundingly intense experiences that we will have to start choosing which to remember and which to discard. Is that new relationship with some divine being less important or more than a specific memory of your mom? Perhaps there would be a core of essential memories that we would consider untouchable, that define our identities, but the rest would have to continually be renewed, the old fading away to be replaced by amazing new things.
Gradually replacing our old selves with new doesn’t sound like such a bad thing, but it is not what is commonly thought of as eternal life. Think of it as a logical extension of what life, as we know it, is like. I am not exactly the same person I was twenty years ago, and I imagine that, after a million years, I would not be even approximately the same person. That is, the old me would be dead, replaced by someone new, someone else who would be unrecognizable to anyone who knows me now. To put it more simply, the person I am now cannot live forever. We are mortal after all.
Crystal Kay, Eternal Memories