Board Thread:Spoilers!/@comment-4877635-20140901190111/@comment-24674051-20141106154309

Seeing these comments brings back echoes of "We Are Both". David and Belle were out of commision during the bulk of the curse, and I don't think they started out with False memories, they just started out with a major case of amnesia. With David, it wasn't until he saw the windmill in Gold's shop that he "remembered" David Nolan. Similarly, After Belle crossed the line, she simply suffered amnesia until Regina pulled the Rabbit Hole matchbook to give her the "Lacey" memories.

One guess is that the Dark Curse has the ability to cause amnesia and cause the people to remember what the curses creator wants them to remember. I think ultimately that was how Regina was able to give Emma and Henry their Memories as well. Since this is Snow's curse, the Memories are under Snow's control (and maybe David, depending on how the shared heart thing works).