I once made the mistake, many years ago, of asking my mother for help with my Latin homework. Her withering response was," I pay good money for you to go to grammar school so that you can teach me Latin!"
The next day a neighbour popped round. My mother, full of pride, said, "Our Michael's doing ever so well now. He's at grammar school and learning French and Latin and Algebra. Go on, Michael, say something to Mrs Jones in Algebra".