Well as long as we are doing crack theories about BF–here’s mine: during the cursed years she operated like that guy in Memento. She didn’t have her old memories, but she did have a set of instructions she had smuggled out of FTL. After all, Regina wasn’t likely to go reading the prayer books at the Convent–and if you need someone who is going to follow instructions on faith–who better than Mother Superior? She wouldn’t have her memories but she would have these notes to herself telling her what to do and when. Rumpel and Regina appear to be the only ones who were able to bring “things”–but maybe BF was able to do it too, but not avoid having her memories wiped.
“If I had a world of my own, everything would be nonsense. Nothing would be what it is, because everything would be what it isn't. And contrary wise, what is, it wouldn't be. And what it wouldn't be, it would. You see?” -- Lewis Carroll, Alice's Adventures in Wonderland & Through the Looking-Glass