Yes, although I'm not sure which theory I believe the most. The one I'm thinking the most is: The possibility of a soul leaving a dead body and being free to roam the universe, uncovering mysteries that cannot be solved before death !!!!
Yes, I do . In India there is ज्योतिष call Naadi Shastra, या Nadi ज्योतिष which talks about your past life and karma of your past life causes action of your this life. The वृत्त of deeds. I have many Dreams of languages I don't know and places I don't know I went and speak या read in my dreams that's weird and I wonder a lot about it. Soul is eternal thing so our soul remembers a lot life after life. I want to answer your सवाल in religious way. I am Hindu, we worship God's and among God's there is deva(god) calls Yamraj . Yamaraj is god of death . He takes our soul and decide whether person should live या die , but this things done द्वारा individual good deeds and bad deeds , आप die but your deeds will be with आप even in afterlife. And the one who die accidentally , they need to spend their life as a soul in bhootal (earth). We know them as ghost and etc.. your this life या हाल का good/bad deeds decides your afterlife so people try to do या perform as much as good karma. If my answer don't appeals आप than forgive me.
If you're a decent person, then something good happens to your soul. If you're not, then something not so good happens. I'm Christian so I think that the good thing that happens is heaven and that the bad thing is hell, but to each their own.
I believe something does happen to our spirits after we die. Whether it's reincarnation, Heaven, Hell, purgatory, etc...we can't actually know until we actually die, right? So quit riddling your brain with this and live life to the fullest at the moment. You're not dead yet. What happens, happens.