Keep your Face to the SunShine
Sometimes we see people shouting on each other for petty matters. When we stand in a queue some person will try to go on the shortcut and when we question him, he starts shouting onus. If the people around us also start shouting on him, he will keep silent. But if everybody is silent the person will try to take the advantage.
If you are fully convinced that you are correct and the matter is serious enough to go for a confrontation, then only come out with your language heavily. Otherwise, just adjust and move forward.
Knowledge is power.
I think healthy discussion is the best source of knowledge. If we engage in such a fruitful discussion, surely we gain knowledge from other people, we can't predict that other person has or has not more knowledge than us until we discuss with him. I like to discuss with knowledgable people. They are walking library for me. I can gain knowledge without studying or reading books. They share their knowledge and I try to grasp their treasure. They are really pragmatic people who render me chunk of knowledge.
In my opinion the best way to discuss with people is that we should have habit of listening to others attentively. It encourages them to express their views and opening the box of their knowledge. If you have deep knowledge of the subject you are talking about, even in this situation it is good for you to listen to him calmly without interfering him and let him speak unless he is exhausted. When he finishes his arguments then you take your turn and begin to pour out your knowledge in a decent way without disrespecting or hurting him. At the end of the day you will see that he recognises your knowledge with heart. You will win his heart and debate effortlessly.
"Life is easier when you enjoy what you do"