戳到痛处的玩笑
[chuō dào tòng chŭ de wán xiào]
This online name 'A Joke that Hurts' implies the user may have experienced or realized some truths through jokes which actually hit the pain point. In other words, this person might have gained some bittersweet enlightenment from what others consider as just a joke, reflecting a sense of self-mockery and sorrow.