We got a new computer for designing printed circuits. (This was before the PC was invented.) So the engineer sent his design off to the printed circuit place to make a board for him to test. The printed circuit guy called and asked "Hey, don't you want gold plated fingers on the edge of this card?" Since it was only a test, the engineer didn't want to pay for gold so he told him no. When the board was delivered, you guessed it, no fingers at all. He had to solder wires to it to get it connected.
So I took one of those boards, printed a bunch of human fingers on the lettering machine, and stuck them to the board. Then I stuck that to a sign saying:
TO ERR IS HUMAN BUT TO REALLY MAKE A MESS YOU NEED A COMPUTER