Years ago, I was helping a landlord jump a truck. Can't remember the lead up, but I said "Black to red, right? Haha", and I hear a loud "pop". Me... "Umm, I was kidding...". This is a guy that's a master plumber, and has several rental properties he takes care of 100%. I'd have given 0% odds of him connecting the cables the way I said. I later found he was functionally illiterate. Not sure what that means in this context, but there was something going on there.