Ok, first, a witty intro (again?).
We often hear people say do not disturb a developer or programmer. But often we do not understand why. It is not the same as disturbing someone who is doing a regular office job. When a programmer is coding, he is actually building a Millenium Falcon lego model in his head. All the parts are assembled in his head in groups. Once you disturb a programmer, all the groups that are built in his head (but not yet assembled), will crumble and he will have to start over from zero.
Take my advice: If you see programmer coding, DO NOT SAY ANYTHING TO HIM. DO NOT EVEN COME NEAR.