One key to getting along well with people is knowing when to say you're sorry. Sometimes little comments or actions can hurt or offend others. Heavy workloads and stress may keep us from seeing how our actions make others feel. The little things can add up. It doesn't take long for someone to hold a grudge and for grudges to grow into conflicts. In most cases, if someone is offended by something you do or say, it's much better to apologize right away. That solves the small problem and keeps it from getting bigger.

http://extension.unl.edu/welfare/apology.htm