I will often tell my opponent my first serve is out, even if he can't return it. I need to know my eyes are correct, my scruples are where I want them, and I play an honest game. He can subsequently do as he chooses.
I often lose in the long run, but victory is not my motivation for playing tennis. Hitting great shots is my motivation.
I often go home really crushed, even winning all my sets, if I don't hit some great shots.
I also can go home really elated, after losing every match and set, but able to hit some really great shots. I obsess over my good shots, try to forget my dumb shots and errors.