I learned this recently. I would end up circling the gas pumps trying to remember if it was right or left. It wasn’t until the person who was on the pump beside me, who also saw me do this circle before getting it right, told me about this feature. I remember telling a friend of mine about it and they told me that they already knew, but no one ever told me about it. Glad to know I’m not the only one who would have to play the guessing game of “which side is the gas tank”.