Had a hell of a week trying to convince a client that "Case Sensitivity" is a real thing in programming languages.

So there was some typo in some third party code which client had provided which was not giving the accurate results, but the client was not ready to listen. I asked him to get the variable rectified from the 3rd party from

var1 to Var1

But he somehow had a notion in the back of his mind that the 3rd party could never ever be wrong and it was surely I who had screwed up the code and he won't even bother the other team.

He was all like "I don't understand anything remotely connected with coding, but do explain me why is this not working ?" (His exact words)
Me (thinking): umm, WTF !!!

After to and fro for the whole damn week, finally able to convince him ( I guess, still doubtful) after giving the video and link of a jsfiddle showing him all the freaking magic of caseSensitivity!