There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened. - The Restaurant at the End of the Universe
It will not surprise you that I don't believe I have ever been to a gas station in my part of Maine that is NOT pump first. You just get all the gas you need and then mosey on into the store to pay your tab.