Have you heard Kim tell the origin story for Radical Candor? When she was living in New York, a complete stranger approached her on the street and Challenged her Directly while also showing that he Cared Personally. Kim was amazed by the interaction, and further inspired by the words the stranger left her with:
It's not mean, it's clear.
Watch the video for the full story:
https://www.youtube.com/watch?v=ViLau3YpVLU
Also check out episode 2 of the Radical Candor podcast for more about this story and Radically Candid criticism.