this doesn't mean anything probably just a freak accident. i feel for your grandpa.
It's simple, You can foresee the future.
Well obviously you cannot see in the future.
You probably had that dream relating to events you already knew, but you don't know you knew this events.
It's like when ppl thing they have de ja vu. Quite often they don't, but when they think back to the dream they think that the dreamed about the present moment when they never. Not like I'm an expert. Maybe you're the me t addition to the avengers.
Sorry about your grandpa.
I guess potatoes is what's actually happening here.
Dreams... impossible to make sense of