Um.. I don't think it happens that often..

[ But she sounds a little unsure with the way her voice trails off after saying it. Madoka quietly thinks on it for another moment, and then decides it might be better to try and explain with an example. ]

I've been here for about.. maybe ten months now? And I was all by myself for months and months until someone from my world appeared here too. And some people are still here all by themselves, even now.