Many programmers have had the experience of explaining a programming problem to someone else, possibly even to someone who knows nothing about programming, and then hitting upon the solution in the process of explaining the problem. In describing what the code is supposed to do and observing what it actually does, any incongruity between these two becomes apparent.
"Hey dude, are you talking to someone?" Nah dude, I'm just rubber duck debugging. "Oh cool, thought you were crazy."
The duck syndrome is where on the surface of things, someone seems normal and are floating along peacefully. However, the truth is that underneath the water the person is paddling feverishly to keep going.
People: Oh dude! Everything in the startup world seems fun!
You: Oh yeah man! I love it, it's super easy. *cries deeply inside*