Yeah, I know, that’s a pretty time-worn chestnut…but, hey, it’s supposed to be a B-movie, so it’s already an achievement that the script offers up any sort of explanation for the sudden change.
And I know someone who knows someone who knows someone to whom that sequence of events actually happened. Although I suspect we all know someone like that, and that no one knows the someone who someone knows, let alone the someone who someone knows who someone knows. So it’s very likely more akin to an urban legend – in the sense that it might happen in real life, but probably only to a far less drastic degree than commonly depicted in fiction.
But in fiction it can work in the most drastic of ways, and sometimes even without causing any adjustment problems to anyone. Unless the script calls for the latter, of course – for example, to use for exposition, as here. Mopey delivers it like a pro, even if it’s an angry pro. Whether she’s angry with herself, for forgetting about Biff’s change, or with the script writer, for making her go through such an implausible bit of exposition, is open to interpretation.
No matter how implausible it was that she kept forgetting, in the first place, she’s now definitely grokked it. The blackboard of eternal repetition is a highly effective tool in that regard, at least in fiction.* >_>
More on Monday.
* Excluding the Simpsons, obviously.