You too? First job, first production push (circa 1997)... a few days pass and support comes into my office with their hair on fire. "Customer is asking why the program is calling them a fucking idiot."
In a piece of code that it should have been impossible to hit, I'd put a dialog "Developer is a fucking idiot".
When I say impossible to hit, it was on the order of if (a == null && a != null ){}. Or so I thought... turns out I'd miscounted the curly braces.
I remember it being graffitti’d at Wean Hall at Carngie Mellon circa 1990. (about half way down architect’s leap for fellow CMU-nies, around fifth floor maybe?).