Richard Brinsley Sheridan said this quote
“ SNEER. But, what the deuce, is the confidante to be mad too?PUFF. To be sure she is. The confidante is always to do whatever her mistress does- weep when she weeps, smile when she smiles, go mad when she goes mad.-Now, Madam Confidante! But keep your madness in the background, if you please. ”