Is there really a wagon?

So, I find myself saying a lot lately, "I fell off the food wagon" or "I'm back on the food wagon today".  But I have to wonder...if I'm on and off almost every other day or whatever...is there really a wagon?  Or am I just torturing myself?  One of my favorite quotes from any nutrition, diet, fitness, etc. book is by Bill Phillips (aka Mr. Body For Life), taken from his Eating For Life book.  He says that it's not what you do some of the time, but most of the time that matters.  So not to beat yourself up about the occasional indulgence, etc., but to stay postitve about eating right most of the time.  I like that...a lot.  :)