Plot Said So

''We don't need a real reason for that — the plot said so! END OF STORY.''

If something that can't be explained by characters without taking an atrocious amount of time, thus killing the story's momentum, happens in the story, we shouldn't have to worry about anything since that whole mess can be sorted out with three short words: Plot Said So.

Moments like these are usually found whenever a Plot Hole needs to be filled with some meaningful substance, but can't be due to such an entity being absent. So if characters can't explain it and the writers can't come up with any witty way to explain it without directly doing so, then the story itself and what happened earlier should be able to.

Plot Said So can also refer to when something formulaic happens due to how clichéd or commonly used it is in (other) forms of fiction and needs no further explanation as you already know what's happening and why. This is UnTrash Wiki's response to many moments that may be thought of as such.