Mine was pretty surreal also. I wrote software for the control room of nuclear power plants. Went with the crew that installed the hardware and software in the first plant. Turned it on, and the first words out of the plant managers mouth was "that can't be right".
It goes something like this: I never wanted to write software for nuclear power plants or the likes where many lives depended the correctness of my work. Then a few years later I met a guy who was quite lax when it came to software security etc. When we talked he mentionend he worked writing code for nuclear powerplants.