Maybe Natasha thinks her marriage will inevitably become like Natasha and Berg's if she waits too long? It seems to suit them, but it wouldn't suit Natasha at all, so of course she's afraid of waiting.

Pierre reminds me of myself sometimes, so my exasperation with him is tempered by the desire to hug him and tell him "It's not that bad, Pierre, really it isn't."

I thought his early conversion seemed pretty sincere. But he definitely spent a long time staving off the realization that Freemasons are more or less as bad as anyone else, which I think he noticed pretty soon after he started hanging out with Freemasons aside from the guy who converted him.