What are the parenting superstitions your grandparents believed in that you as parent practice as well?

Picking a good name -- my grandparents and the generations before them believed that if the name chosen for the child is not appropriate, the child will not grow up "right" -- for example, a child grows up always sick because his parents supposedly gave him the wrong name. The moment his name is changed, he gets better. Do I fully believe in this -- No. But psychologically, a child's name has a heavy bearing on his life as it is something that follows his throughout his life. My interpretation of this is that if you pick a name that is too outlandish or weird for the sake of trends, the child will have to deal with the consequences. I've cousins who have really "interesting" names which they hated. They gave themselves nicknames in school because no one could pronounce their names and everyone was always making fun of them. Really did a number on their confidence and self worth. What made it worst, their parents who bestowed them the name, would also use a nickname instead of the child's real name.