There is a game within the game. This first happened to me in the 1970s. I was in a tie-breaker in a doubles final and my partner asked me about someone in the third row watching the match. I made some comment and he laughed. One of our opponents freaked out and skipped like three shots in a row. Turns out he thought we were making fun of him.
Later in my career as a player, my hip was shot. I could not return serve so I would take ten seconds to receive serve many times. My opponents would comment I was trying to “get in their heads” is how they put it. Nothing was further from my mind, until they mentioned it! I was trying to get the serve back to the front wall and I really needed to focus on that.
Okay so the point is, if you are thinking about what your opponent is saying or doing, you are not focused on your play. The world is not out to get you. An opponent is playing you in a game. A game! Even if your opponent is making fun of you, if you dwell on that, your are ruined. Even if your opponent is trying to “get into your head” stop thinking like that! If those things affect us as players, we are defeating ourselves, and helping our opponents!