Pride, ill-nature, want of good sense, arrogance and impatience are the sources of ill-manners. Good manners are a part of good morals. They are rare gifts. They easily and rapidly ripen into morals.
Be simple, humble and unostentatious. Say little or nothing about yourself.
From "Daily Sayings" by Swami Sivananda (1987-1963). More Informations on Swami Sivananda: on the Website of Divine Life Society, Photographs of Swami Sivananda, German Pages on Swami Sivananda