There isn't any rules for photography. It's a guideline. You don't have to follow that for every single picture that you take. If you see a picture that would look really good, don't be afraid to take a lot of shots of it! Take them while applying the rule of thirds, without, upside down, anything you want. That's the fun of photography: take as many as you want and have fun with it. You can never go wrong with photography. Ever