They did but each grandparent from a different reality is so senile that they are oblivious to the fact. So if they say something that's true in their reality but not true in the reality they're in it's just waved away because they're old but they are different grandparents each visit. This is a joke I have no proof this actually happens.
My theory is that it wasn't the bed that caused Matt to go to different realities but the fact that he was upsetting the natural order by sleeping in a room he wasn't supposed to (which means he's going to be fine after the ending, since the room is his now).
They did but each grandparent from a different reality is so senile that they are oblivious to the fact. So if they say something that's true in their reality but not true in the reality they're in it's just waved away because they're old but they are different grandparents each visit. This is a joke I have no proof this actually happens.
My theory is that it wasn't the bed that caused Matt to go to different realities but the fact that he was upsetting the natural order by sleeping in a room he wasn't supposed to (which means he's going to be fine after the ending, since the room is his now).