Originally Posted by stafs:
“I think it has something to do with the Doctor being a time sensitive being. While the Slitheen were still a threat the future was uncertain so there was no fact to remember, hence his fuzzy memory. It wasn't until the Slitheen were defeated that the Harriet's future as assured and suddenly the Doctor has complete recall of Harriet's future.
Anyway, that's my theory and I'm sticking with it.”
That's a very interesting and original idea.
I'm not sure if it will turn out to be correct, but it's a very good idea all the same.
Much more plausible than the fading photograph in "Back to the Future".
The Doctor's memory being fuzzy at first, and then when the future becomes more certain, specific parts of his memory become clearer and more lucid....Very good.
Very good idea, and more plausible than other ideas that get used in science fiction.