past time: Making jokes on programmer humor forums about the jokes being told on the humor forum.

fall out: Autists who don't get the joke of the joke and genuinely think they need to explain the original joke even though it is "obvious" it was a play on words.

struggle: Resisting explaining to them the joke on the joke. And if I break down and explain, trying not to be a condescending prick. Most of the time I don't respond.