You finally booked the court. New racket, fresh can of balls. The first few minutes feel great.
Then the ball comes back. You swing, and it clips the frame. The next one sails over the fence. Your partner spends more time picking up balls than playing. You laugh it off, but on the way home you wonder if you're just not made for this.
So you watch videos. One says turn your shoulders. Another says watch the ball. A third talks about lag, pronation and kinetic chains. Now you have twelve things in your head and the ball still goes into the net.
The problem was never you. You were given too much at once.
I've coached tennis for about ten years. Almost every beginner I meet goes through exactly this. And almost every one of them gets better the moment we throw out the long list and focus on a single thing.