Regarding reading up side down: I worked with an old gentleman who noticed that I could read up side down. He told a story of when he was young, he couldn’t afford to buy a newspaper, so he would sit near a gentleman on the bus that would read the news paper. It was folded back, and my friend needed to read up side down to pirate the news from this gentleman. He regarded up side down reading as highly as reading a different language. This coming from a man who read and spoke four languages.
I used to use reading upside down as part of the interview process in hiring software engineers. It shows one has good spatial relations and language skills. I’d write on a piece of paper, “If you can read this, you still have a chance in getting hired.” I’d have it facing me, so it was upside down to the interviewee. He would get bonus points for asking about it. I like people that have the guts to say what’s on their minds, and if they could read it, it most certainly would be on their minds.