A good upbringing means not that you won't spill sauce on the tablecloth, but that you won't notice it when someone else does.
Anton ChekhovNot everyone knows how to be silent or to leave in good time. It happens that even people of good breeding fail to notice that their presence provokes in the weary or preoccupied host a feeling akin to hatred, and that this feeling is tensely concealed and covered up with lies.
Anton Chekhov