I think most of us need to be somewhat delusional about our games or we would quit playing all together! There are definitely times when I think that I should quit cause I was soooo bad, but then I have a good match and I think, maybe I still can improve!!! That is probably very delusional!
Anyway, the player I played last weekend week singles in a tournament is a perfect example. She self rated at 3.5; played up to 4.0 and was at best a 3.0 player. I beat her 0 and 0 and felt kind of sad doing it.
She kept saying that she was sorry that she was playing so poorly when she just could not hit a groundstroke that would stay in the court and then when we were done, she stated that she was really used to playing against players who hit a lot harder than I do so that she was at a disadvantage. In warmup, I fed her balls and every ground stroke went out by about 2-5 feet.