Is it a general consensus thing? Could it come down to the old herd mentality, as in, if everyone else thinks it's right then it must be? Is something right because you really want it to be right, or because it fits your agenda? Does it boil down to the perceived view that if there is an overwhelming stack of evidence that supports your view, you must be right?
So I guess the answer lies within the source of your evidence. And how much you truly trust, or maybe shouldn't trust, that source (be that the media, the government, medicos etc), which inevitably proves that
@globaleagle is right in believing his dad's words of wisdom. Unless it is directly related to yourself, you can't comfortably claim to be right about anything.
So, if you can't truly claim to be right about anything that is not directly related to yourself, how silly is it to make an even more ridiculous assumption that someone else is wrong in their opinion? Maybe not. If we are willing to accept that we may not know what is right in any given situation that we are not personally involved in, then we may be doing that other person a great justice by letting them know they are wrong in their belief that they are right.
Unless of course, they are telling you about themselves. lol