This tone of this thread has gotten me thinking about a a few human traits.
In engineering we used to get ahead of the argument game by designing tests, finding failures, creating possible solutions, testing them, analyzing results, and then repeating as necessary. It was usually (sometimes) straightforward to find out if we were right or not, and we found that test results trumped opinion every time. Then we just went got on with it. Winning was being correct because it was better for the system to work than not!
However sales is not the same as engineering. Winning is convincing the customer that you offer something superior and getting them to give you money for it. As an consultant I found myself having to do both. Selling myself to get jobs, and then actually making something work. The two thought processes were so diametrically opposite that I found it took me some time, weeks, to switch my mind completely from one to the other, and weeks again to switch back.
Once one has put a lot of time and thought into something, and finally made a decision, it is psychologically very taxing and sometimes impossible to take in new information, especially if it fundamentally opposes your hard thought out decision.
It is helpful if we can learn from the experience of others but sometimes we really can only learn from our own experiences. I know I had to, I trusted smart people who wrote books showing how they were right and others wrong, people in expensive suits who apparently spent a lot of money, people smarter than the markets, etc. We look for these parent figures. It takes a long time to find that they are not there.
I know in my early years I used to study tricks on how to "win" an argument, only later finding that in real life winning the argument usually meant you lost something more important.
Creepy but good link for what a "good" FA should do.
3 Ways to Convince Anyone of Anything - wikiHow