"Denizens of our little town, before, had little reason to try to leave. But misfortune would befall anyone who tried to leave."

Mister Gold was quite content to handle his business in town and utilize his connections and resources to have others handle matters outside of Storybrooke.

"After the curse fell, anyone of us that crossed the border would lose our memories and return to being our cursed selves again."

And that was just the start.