When playing tennis, there are a limited amount of things you can control.
Most of them happen on your side of the court. The way you hit the ball. The angle of the racket when hitting the ball. The power and direction you want to give the ball. Whether you are going to run for the next ball or leave it be. And possibly few more.
When the ball leaves your racket, though, your part is done. There are an infinite amount of variables on the other side of the court you cannot control. The final trajectory of the ball, the response of your opponent, the call of the line umpire, the decision of the chair umpire, the impact of the weather, the variable of the net. The outcome of the shot is in large part unpredictable.
And that’s true also of your work. Whether what you do is going to be successful or not is largely not up to you.
Focus on your side, perfect what you can impact, make sure you have the best possible chances in the best possible context.
Then be happy with it. You have done your part.