Here's the deal. If the first thing out of your mouth on the first day of the month is “Rabbits, rabbits, rabbits”, you'll have good luck for the upcoming month. I'm not sure when I started doing this. I don't think my mom taught me, but somewhere along the line, I heard about it and did it and taught my little sister, Lin, to do it as well. Here we are 50+ years later and we still do it. In fact, we compete to see who will be the first to remember to say it on the first of every month. At present, I have a leg-up since the first of each month currently arrives here in Durban earlier than it does in Boston. Big sister/dateline advantage!
I always wondered if other people did this, too. When I was in university, some of my fellow students were rabbit fans. I met some first-of-the-month rabbit-ers during my working years and I've even met a few yachties that participate in this odd practice, despite the fact that rabbits are considered bad luck on a boat.
I was interested in the origins of the “rabbits” superstition and was surprised (though not really) that Wikipedia had an article on it and there were several more articles as well. Lots of people do this, evidently. "Even Mr. Roosevelt, the President of the United States, has confessed to a friend that he says 'Rabbits' on the first of every month—and, what is more, he would not think of omitting the utterance on any account." – The Nottingham Evening Post. 27 November 1935
Though the origins of the practice aren't clear, there's been reference to it in literature since at least 1909. There are variations on this theme, but basically it's all rabbit-oriented. Perhaps because some consider rabbits to be good luck … like a lucky rabbit's foot?
The White Rabbit Theory (really?) postulates that it might be as old as William I. An article in Yankee magazine mentions possible 13th century British origins. Even NPR did a piece on the rabbit tradition. I'm feeling like I'm in good company.
I'm not really sure I've had good luck each month whenever I've remembered to say it, but I haven't had bad luck either and I hate to tempt fate. So … if you're a “rabbits, rabbits, rabbits” advocate, let me know. If not, tomorrow's the first of the month, give it a try.