one theory i heard was about instant reincarnation. people who claim there's a light at the end of a tunnel is actually the birth canal. i like that idea, but at the same time i believe in spirits so i don't think it's that instant [but if it is i'm fine with that too] i believe we die and go to summerland [or something like that] where our soul can rest and reflect on its previous lifetime. sometimes we die suddenly, or our spirit doesn't want to let go of the physical and it lingers [hence spirits/ghosts] but once we are ready to be reborn, we are. we don't really choose as what, it's just another experience out souls have and we learn from.