Programmer: the people having dirty bottoms
A skilled craftsman has specific body, especially hands. Their hands are always atypical. For example, a master turner's finger has gone, a patisseries hand is smooth by oils and fats, and an indigo dyeing craftsman have hands with dyed blue.
Then, how about a programmer? They sit in their chairs and never walk around, so their buttocks have bad blood circulations, discolored skins, and blotches. Programmer's craftsmanship shows up in their buttocks.
@i05