That means that your mom/dad never existed, that means that you never existed-> so you are never able to kill your grandparents soooo your mom/dad exists -> you do to. But than you can go back in time.... you know where this is going to... soo what would happen if you went back in time to kill your grandparents
well i would have already did it, which i didn't, which means i will not. i'm not sure if that answers your question