You are NOT Right!
In my younger years, I remember thinking about how odd it was for people to accuse others of always thinking they were right. This was meant to point out a flaw in that person's character. But this reasoning didn't make sense to me at the time.
I thought to myself, why would anyone make an assertion for something that they thought was wrong? By that reasoning, I concluded that everyone must think they are right. To a point, I still think that idea is true in the simple sense that I thought about it at the time.
I understand that there may be some situations where people subconsciously or consciously pick the other side of a discussion/argument even if they don't think they are correct. These circumstances would occur if someone has an ulterior motive. But that is out of the scope of what I would like to share today.
If we can ascertain that people generally think that they are right when a discussion or argument then why is this accusation derogatory? I have concluded that it isn't the act of thinking that they are right that is the issue, it is the act of not being open to other possibilities.

As a note, I will likely use the term argument most of the time from here on out, but this could be true for any discussion on a topic that people have differing views.
Let's look at the way that most arguments occur. First, people have an argument over something that has occurred in the past. Second, people have an argument over something that is going to happen in the future. The first type of argument can sometimes be settled easily if the situation that already occurred has been documented. You could simply look up what the fact of the matter is and settle it there. However, as with most things, everything is subjective so some things cannot be proven so easily.
Researchers at Bielefeld University, Oxford University, and Aix-Marseille University concluded after their study that, "... our brain captures a wide range of distinct sensory stimuli and links them together. The brain has a kind of built-in filter function for this: sensory impressions are only integrated if it is necessary and useful for the task at hand."
With this information in mind, we should be able to conclude that each person will process different information from the same given scenario. Simply put, we can experience the same thing at the same time and have two completely different realities of what has happened in the past. For that reason, I believe that nobody can argue their side of something that has occurred in the past unless it is a simple fact that doesn't have any room for subjective interpretation.
Next, the second type of argument should be even harder to prove. Here, we are looking at things that will happen in the future. I believe this is how most arguments occur. One example might be where two people need to decide on the next move that will put them in the best position for success. Even if they have the same vision for the future, it is simply impossible to know what action will result in that vision.
The way we determine our assertion at this point is by using past experience to formulate a prediction of what is likely to occur in the future. However, the future may play out completely different than what has occurred in the past. We oftentimes will seek counsel from someone with more experience in these situations because they are better equipped to make an accurate prediction. However, once again, this may not unfold the same way that even the experienced person predicted.
It is clear in my mind that people cannot be right (at the time of the argument) about something that will happen in the future. Even in the future, it is likely that neither of them had the exact correct answer. In hindsight, we can always find something that we could have done slightly differently to achieve a better outcome.
So, if we can agree that none of us can be 100% right all the time then should we just give up and try not to make any decisions? Of course not. As I alluded to earlier, we make predictions to try to achieve the best outcomes possible. We should use our experience and the experience of others to help us formulate the best course of action to take. The important part to know during a disagreement of any kind (or really any situation that is foreign to your current beliefs) is that it is impossible for you or the other person to be 100% right. Everything is subjective and most times the best possible outcome is one that people make together. Therefore, think of disagreements as a great opportunity to learn why the other person believes what they do. Try as hard as you can to practice empathy and put yourself in their shoes. You will likely gain understanding about this world by understanding their past experiences and beliefs. Over time, you will gain wisdom by learning from others as opposed to trying to learn everything the hard way through your own painful experiences.
Keep an open mind with others, practice empathy, practice compassion, and be willing to change your beliefs when confronted with the eventual reality that your truths are not quite as true as you once thought.
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."
-Mark Twain
Link to the study mentioned above:
"How the brain integrates sensory input" -Bielefeld University