@ hjbau: I think only those who were cursed couldn’t leave or enter SB, because Henry was clearly able to leave and enter SB. Emma arrived, and she wasn’t under the curse. I think Emma coming simply started time again. August could have possibly visited SB even before Emma came. He implied as much in the diner scene when he hinted he’d come to SB for inspiration. It makes me think he’d been there before. Regina also said he was familiar. Yet, we still need more information.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy