A story from the time recounts that Piero Soderino, the head of the powerful Florentine Republic, even told the famously irascible Michelangelo that David's nose was much too large. Michelangelo then hid some marble dust in his hand, climbed back up his ladder and pretended to do some more "chiseling" on the offending proboscis. While he did so, he let some marble dust fall from his hand. The pompous Soderino was foo…
Not a huge Steve Jobs fan, but I had a professor who had worked as a designer under Steve Jobs and tried something similar. Steve insisted that a new mouse needed to be just a fraction of a millimetre slimmer so a person's palm was lower and closer to the work surface. They figured he was being an unreasonable "delicate genius" and returned a few days later with the identical mouse and claimed they had reworked it to…
Sen no Rikyu, a tea-master, wished to hang a flower basket on a column. he asked a carpenter to help him, directing the man to place it a little higher or lower, to the right or left, until he had found exactly the right spot. "That's the place," said Sen no Rikyu finally.
The carpenter, to test the master, marked the spot and then pretended he had forgotten. Was this the place? "Was this the place, perhaps?" the carpenter kept asking, pointing to various places on the column.
But so accurate was the tea-master's sense of proportion that it was not until the carpenter reached the identical spot again that its location was approved.
from here: http://www.ashidakim.com/zenkoans