A long, long time ago, when I was still in school, or perhaps when I was attending yeshiva, or NCSY, or camp, or something, I heard a story about an old Rabbi who once irritated a librarian while bentching and, because of the events that followed, later sent her an anonymous note, a note that quite unintentionally convinced the librarian to cancle her plans to marry a non-Jew.
The story was presented as true. And naive teenager that I was, I saw the old Rabbi's note as a wonderful illustration of the famous saying from Chagiga 15: "Every day a bas kol, a heavenly voice, calls "shuvu banim shovavim, return to me my wayward sons."
I should have known better. Rats.