I don’t mind discussing something whose opinion is different from mine; in fact, I generally enjoy it. There are two exceptions, however:

• I have nothing but disdain for people whose opinions are not their own. I’m sure you know who they are: the ones who are merely parroting someone else’s opinion without giving any thought to why it might be right or wrong. They don’t form opinions; they just pass them around.
• People who only repeat their opinion in an ever-louder voice, not even hearing what you are saying. I refer to these people as “foghorns.”