a belief in a celestial teapot is meaningless because it doesn't matter whether it's false or not: you have no evidence and no reasonable way of gaining evidence. Claiming to believe in it is just a waste of cognitive resources. A belief in, for example, the door opening inward or outward is meaningful: It will directly impact the action you take when you come to the door. This is regardless of whether the belief is false, and you push a pull door or the belief is true and you correctly pull the pull door.