Wagner's MBA Law of Milking Mice

Wagner's MBA Law of Milking Mice: Don't try to tell your Grandmother how to milk mice! This is an old expression of my Grandmother Hise (i.e., her invention) that my Mother still says. It basically means to shut up, listen, and show respect to your elders, instead of lecturing them about things on which they are already experts, such as saving money or making the best of an unfavorable situation, etc.