How to gain the upper hand in an argument?

Very easy. Start accusing your opponent of something. "You just don't respect me!" "Why are you raising your voice?!" "You don't understand me!" The main thing I advise is to say phrases of this kind as calmly as possible. And the cherry on the cake is your beautiful French exit, that is, suddenly turn around and leave without saying goodbye after one of the phrases. And no, you will not look like a fool.