You’ve probably heard of this idea. There’s a teleporter which destroys your body and recreates it, in exactly the same pattern but from different elements. If you use the teleporter, is the ‘you’ that comes out really you, or an exact copy? It’s discussed here on Wikipedia.
Anyway, if someone did invent a teleporter like that, I think I’d be scared of using it until after the first time.
This is strange, because in using it I wouldn’t have gained any new information. I already know that the person who would come out of the teleporter would have my memories and believe themselves to be me.