With apologies to Jeff Foxworthy . . .
If, when you talk about "The Good Book," you mean the dictionary, you might be a grammarian.
If your car has a bumper sticker that reads "split atoms, not infinitives," you might be a grammarian.
If you write letters to your local newspaper about spelling errors in headlines, you may indeed be a grammarian.
If you've ever said the words aloud, "You can't be 'very unique,' something is either unique or not!" Then you are probably a grammarian.
If you find yourself editing shopping lists, you might be a grammarian.
If you stop your car on highways and curse grammatical errors on billboards, you might be a grammarian.
If you've ever taken out a Sharpie at a diner and crossed out those apostrophes around "Tips Welcome," you're probably a grammarian.
If you've ever corrected a letter from your company CEO in revisions mode and sent it back, then you might be a full-time grammarian.