Most dev's don't go back to step 1 when interrupted. They go to checking out hacker news :)

It's very hard to go back to step 1 when you can't reasonably hope to get something done before the next interruption.

Yup. Sitting here in an open plan work area reading about open plan work areas on HN. Maybe once everyone goes home I can get some work done.

Guilty as charged.

For those like me who're susceptible to software fences around unproductive behavior, HN has a useful "antiprocrastination" option available under your profile settings.