I organized some seminars by people who'd worked on other systems. And Feynman used to come. And one day a chap from a well-known computer science department came to speak. I think he was a little tired, and he ended up giving what was admittedly not a good talk. And it degenerated at some point into essentially telling puns about the name of the system they'd built. Well, Feynman got more and more annoyed. And eventually stood up and gave a whole speech about how "If this is what computer science is about, it's all nonsense...."