Re: How do you know...
Why are you speaking in riddles? Why don't you answer the question of where in that joke you are laughing at yourself? If you are black, the answer would be "I am black and I thought the joke was funny, therefore I was laughing at myself".
The joke was not appropriate for this board, even if you think it was funny. It violates the board policy as stated in the USAGE POLICY section. That is plain and doesn't appear to be subject to debate, no matter what color you are.