Do you know watt? I was thinking that I was sure there was a famous comedy routine that used that joke and I was racking my brain to remember who did it. I had a vague recollection it might involve Abbott and Costello. After Googling for a bit, I realised the significance of the title of this thread.
So here it is.
https://www.youtube.com/watch?v=kTcRRaXV-fg
