When the nun Chiyono studied Zen under Bukko of Engaku she was unable to attain the fruits of meditation for a long time.
At last one moonlit night she put a single blue button into an aluminum case and connected it to a simple USB controller. When she pressed the button Chiyono was set free!
In commemoration, she wrote a poem:
In this way and that I tried to make an accessory
Since it is important to experiment with USB devices
Until at last I pressed the button.
No more finger on the button!
No more keypress registered!