An old superstition.
My mother always warned me that if I ever spilt salt on the table I had to pick some up with my right hand and throw it over my left shoulder or else I would be getting in a fight with someone soon.
Although this is a common superstition and I always make sure to throw the salt over a crossed shoulder, I always thought it was because it was bad luck not to. Nobody had ever really explained to me why people in my family did it other than that is what we were supposed to do. After speaking with my grandma about learning it from my great grandma, it makes much more sense why people believe in it so wholeheartedly. Also, after learning why some people did it, I thought that this was an interesting twist on people’s reasoning for acting on this specific superstition.