Life after death

Who knows what happens after death? A person can only guess. Some believe that when you die you come back as someone else or something else; so when your body dies your spirit goes into a thing that in that moment is being born.
Some believe that when you die your spirit goes to a new place; Heaven if you're good, or hell if you're bad.
Some believe death is the end, when you die, your body is simply disposed of and after time you will be forgotten.
But what if life and death was just a long dream or a state of someone's state of mind? What if you never actually die? So when you die you carry on your life as normal despite the fact you're actually dead, or so everyone thinks. All your friends will go to your funeral in the life you were in, but your completely unaware as you just carry on your same everyday life.
There will never be any scientific proof of what happens when you die. No-one is alive to tell the tale.