95% of the time I do not care and it's about the journey and not the destination BUT depending on how the story is constructed it is at least theoretically possible to ruin an experience knowing what happens at the end, this is why I tend to find prequels not terribly compelling - if a prequel character is not in the original work, then you know they are gonna die or something, that sort of thing, anyway even when I do care I'm still not one of those people who gets angry about it, that is just strange to me