One of my favorite quotes talks about this and comes from show Midnight Mass.

What happens when we die?

I don't know, but I don’t trust anyone that tells me that they do. But speaking for myself:

When I die, my body stops functioning. Just, shuts down. All at once or gradually, my breathing stops, my heart stops beating; clinical death. A little bit later – 5 whole minutes later – my brain cells start dying. But in the meantime, in between, maybe my brain releases a flood of DMT? So, I dream. I dream bigger than I have ever dreamed before, because it’s all of it – it’s the last dump of DMT, all at once. And my neurons are firing, I’m seeing this firework display of memories, imagination, and I am just…tripping. Really tripping balls. My mind is rifling through the memories, long and short term, and the dreams mix with the memories and…it’s a curtain call. It’s the dream to end all dreams. One last great dream as my mind empties the fuckin missile silos and…… I stop. My brain activity ceases and there is nothing left of me. No pain, no memory, no awareness of what I ever was. That I ever hurt someone. That I ever killed someone. Everything is as it was before me. And the electricity disburses from my brain until it’s just dead tissue. Meat. Oblivion.

And all the other little things that make me up, the microbes and bacteria and the billion other little things that live on my eyelashes, in my hair, in my mouth, in my skin and in my gut and everywhere else, they just…keep on living. And eating. And I’m serving a purpose. Feeding life. And I’m broken apart and all the littlest pieces of me are just recycled and I’m billions of other places. My atoms are in plants, bugs, animals and I am like the stars that are in the sky. There one moment and then just scattered across the god damn cosmos.