In my blog post about Emacs keybindings https://www.wilfred.me.uk/blog/2018/01/06/the-emacs-guru-guide-to-key-bindings/ I mention the 'Emacs Guru Test'.
It's a cute way of seeing how well you know Emacs, so I'm pleased to have shared it. I didn't invent it though. My googling has totally failed to find the original author.
