Ever died in a dream and then woken up? That just means an alternate you in a different timeline has died. Dreams about yourself are a glimpse into what's going on in alternate versions of yourself. This also would explain why sometimes a person can dream of something, and then have it happen later. You simply have to choose the actions in the dream, and you become the version of yourself from your dream. Your timeline becomes his timeline, and vice versa. Try to be more careful, though. Also, be mindful of what happened to those versions of you who died, will you? Remember: the waking you is also the dream of another sleeping you.