People that believe in reincarnation, why do you believe in that?

For the same reason as people who believe in religion, comfort against the scary reality of the fragility of life.
- So you believe in it even though you don't?

The physical law of the “do-over”
- what the heck law is this?!
  
  Mulligan's Law, does not go well on chicken sandwiches as opposed to Cole's Law.
  
  Just science, that’s all.
- "Only second chance I know is the chance to make the same mistake twice."
  -Davd Mamet

I don’t believe in it in the traditional sense, but I do have a feeling that there’s something deeply mysterious about our minds and consciousness. I wouldn’t claim with absolute certainty that death is the end of experience.
Take general anesthesia, for example - it’s one of the closest things to dying that we can experience and still return from. What does it feel like? Nothing. By definition, it cannot be experienced. You might have been under for ten hours, but from your perspective, you simply go from feeling drowsy to waking up in another room, with no sense of time having passed in between. You can only experience being, not not-being.
Who’s to say something similar doesn’t happen when you die? Your experience could simply continue elsewhere. Whether it happens instantly or after a ten-thousand-year gap is irrelevant - because from the standpoint of your subjective experience, it would feel instantaneous. We could take this even further and consider the possibility that consciousness is something universal - something we merely tap into rather than generate individually. In that case, who’s to say you weren’t “born” this morning into this already existing body, complete with prior memories of a past life, simply continuing from where “someone else” left off?

I don’t believe in reincarnation in the sense that I can be born again on this planet as a dog or something. More like whatever makes you “you” was possible in a universe where it probably shouldn’t have been possible. I believe in the Big bounce theory even though a lot of evidence says this is not true, the universe is definitely expanding at an insane rate. I like to think that all matter in the universe eventually comes together in one supermassive black hole and somewhere in that matter soup, another big bang happens. Maybe this time around life doesn’t happen, but maybe after a trillion iterations it does and whatever makes you “you” could happen again. You’d have no memory of it, you’d just be aware of being alive again. If there is just the heat death of the universe and nothing ever happens again then so be it, I was fine before I was born anyway.
- I like to think that all matter in the universe eventually comes together in one supermassive black hole and somewhere in that matter soup, another big bang happens.
  Why do you like to think that?
  
  I’m not religious for a start so I don’t care for an afterlife. That sounds even worse than current existence. The universe itself starting from nothing though is hard to imagine. So I guess my reasoning is that I think it was always there, just slowly expanding and retracting for eternity. Somewhere in that mess, life happened. Maybe it was a one off and maybe not.

I don't believe in reincarnation, but my mother did, based on childhood experiences. It sounded convincing to me as she told it.
Personally, as far as I can tell, when you're dead you're dead.

I want to believe in it because the thought of hell or oblivion fucking existentially terrifies me. I like being a human. Or at least a sentient self aware creature.
But I don't know what to believe because I don't know the truth. :(
- In case you're not aware having your memories completely deleted is the same as death
  
  if I got full amnesia I would technically no longer be myself but I'd still be alive

I forgor 💀

How I see it is that you are meat "matter" right now. When you die your meat matter is eaten by worms and flys (maybe). Some worms and flys then become part of the animal that eats them. Some of your meat matter becomes plant matter. You are not you anymore but you are now other parts of this earth. Obviously there is no consciousness that follows but your energy and your matter live on in different forms.
Edit: maybe there is a spiritual side that moves on a different path from the meatbag side which moves into a different vessel to experience life and the universe in a different way?

I don't believe in it, but here's a very popular short story that uses reincarnation in a clever way:
https://www.galactanet.com/oneoff/theegg_mod.html
- I love Andy Weir

I don't necessarily believe in it, but I have had the thought that if it was real the reason it hasn't been proven could very well be that it's super duper hard to come back as a human and not as, like, a protozoa or even be on Earth. The universe is pretty damn huge; possibly infinite. The chances of coming back as the same thing in the same place are exceptionally small.

My thoughts was from a comic a while back that each time you die you are reborn into someone else, any time, and place, the concept was that you are everyone else but without the memories of your previous yous. And the point was to learn and understand every view and everything.
The reason is because it made me more accepting and humble to others thinking there life is mine just born different with different circumstances.
- "The Egg" is an interesting thought experiment and encourages empathy with others (much needed), however in my opinion it doesn't make sense as a religious belief in a few ways.
  Primarily, what's the point? If "our" soul/spirit/essence doesn't remember our past lives, we aren't able to evolve humanity with the aggregated experiences and wisdom. The benefit implied by the story would be a grizzled singular soul with the experience of every human who ever existed... But to what end? Are we a training program for an advanced AI model created for the benefit of another dimension?
  What about proto-humans such as neanderthals? Hominids and every mammal in preceding evolutionary chain? If anything, the egg would refer to the collective lives of every living creature to have ever existed. Even single-celled organisms? Alien life forms?
  Third, you & I exist now, in parallel. I can't be you while also being me, unless the royal "we" is not a singular entity but rather a multi-threaded process feeding something one layer up. This might go back to the AI modeling concept, and perhaps "simulation theory".
  If we are a simulation to train or experiment via advanced civic AI model, we individually are expendable iterations. Data points in a massive soup of existence, itself being one of a multitude of similar simulations.
  Do what you can to improve the existence you reside in and those sharing it with you.
  
  I know ~~where~~ I'm not in a simulation because of the shadow test, I learned that from the reading the Veritas.
  Ok, ok, seriously, there's flaws with every religion or thoughts after death and all that, but I like this one even though it probably isn't true because it helps me remember to try to help others and be kind and know others have lived different then me and helps me remember to be sympathetic then judge people.
  
  You are in parallel rn. All your cells are independent living beings all doing their thing. They might be part of structures, tissues, or-gans. Each one alone is not you. Almost all cells are completely unaware of the majority of the other cells. A cell in the muscle fiber in your foot has no awareness of a cell in the retina of your eye. In fact, none of the cells have any real awareness. But when they all act in parallel, you come about. Imagine that, but with all life. Maybe there's an emergence that comes from that.
- I remember a comic too, but the original story is The Egg by Andy Weir. https://www.galactanet.com/oneoff/theegg_mod.html
  If there is a comic and someone finds it, please link it.
  Edit: found a comic by voldult on Webtoons, but that isn't it. I remember a denser, darker style. Now I'm doubting my memory. Maybe I just read the story and imagined a comic based on the cover art?

I only believe it to the extent of:
It doesn't make sense to:
Not exist --> Exist --> Not exist
So I'm just (baselessly) theorizing that existence is more like:
Not exist --> Exist --> Not exist --> Exist --> Not exist [Repeat... forever]
I think if you die, there is some unmeasurable energy that transfers to living being that's born around the same time and area where you died. Like, scientists couldn't see atoms until recently, maybe there is like some "soul" or whatever thay haven't been measured yet.
But that's just a theory, Lemming theory

I recently (re-)read Robert Lanza's "Observer" and there are some trippy ideas in there that have me rethinking what reincarnation could mean.

I've sort of always believed in reincarnation, though I can't recall the first time I was introduced to the concept. I feel like the universe is very cyclical, so why not reincarnation? Although I guess I'm not sure how much of us gets "carried over" into the next life. What makes us "us"? What part of us would be passed on to the next life? I definitely feel like I've been here before, though it would be hard to explain why, and perhaps I'm just mistaking that feeling.

I'm an atheist so I don't actually belive in reincarnation, but it's a nice idea. I get the appeal.

I think when we die, we rejoin the essential je ne sais quoi of what makes reality what it is. It wouldn't surprise me if that essence is reused in other things. It won't be me, as I am now. It'll be parts of me and parts of everything else, making something entirely new.
- Yeah, this is what I think too.

I don't, but a compelling story is presented in The Egg by Kurzgesagt. https://youtu.be/h6fcK_fRYaI
- The Egg has to go through a LOT of cyanobacteria. Of course it could just be that patient.

What if we're all different parts of the same thing, so no one really dies. You instead get absorbed back into the big life thing, things get rearranged, and life comes up somewhere else with a little bit of you and a bunch of other stuff mixed in? There is no death. Just a new mix.